Differences in the Microbiological Profile of Raw and Pasteurized Breastmilk from Hospital and Community-Based Donors at the First Human Milk Bank in Vietnam.

Background: Microbiological quality is one of the key safety standards in human milk bank (HMB) operations. We describe the profiles of bacteria in donor human milk (DHM) before and after the pasteurization of samples collected from breastfeeding women in the hospital and from the community in the first HMB in Vietnam. Methods: Data were collected between February 2017 and January 2022 from an online HMB monitoring system. First, DHM samples were cultured, and the number of colony-forming units (CFU) were counted before (n = 708) and after pasteurization (n = 1146). The gram-staining method combined with the Vitek 2 Compact system were used to identify types of organisms at the Da Nang Hospital for Women and Children's Laboratory. Passing criteria for DHM included pre-pasteurization samples had a total colony count <105 CFU/mL and post-pasteurization was <10 CFU/mL. Results: During five years of operation, Da Nang HMB had 491 donors (48.7% were hospital and the rest community donors) who donated an average amount of 14.2 L over 45 days. Of this DHM volume, 84.9% of donor samples passed the pre- and post-pasteurization microbiological tests. DHM from community donors had a higher pass rate (87.8%) compared to that from hospital donors (79.5%). Before pasteurization, 15.4% of DHM samples had a bacteria count <103 CFU/mL, 63.0% had 103-<105 CFU/mL, and 21.6% had ≥105 CFU/mL. Most of the unpasteurized DHM samples (93.0%) had microorganism growth: with one organism (16.4%), two (33.9%), three or more (43.6%). After pasteurization, 17.9% samples had a bacteria count of 1−9 CFU/mL and 7.2% had ≥10 CFU/mL. DHM samples from community donors had a lower bacterial count and number of organisms than those from hospital donors both before and after pasteurization. The highest microorganisms from unpasteurized DHM samples were Staphylococcus epidermidis (74.2%), Acinetobacter sp. (52.1%), gram-positive bacillus (51.7%), Staphylococcus coagulase-negative (15.8%), and Staphylococcus aureus (10.5%). Common microorganisms from pasteurized DHM were gram-positive bacillus (21.0%), Staphylococcus epidermidis (3.9%), and Acinetobacter sp. (0.9%). Samples from the hospital tended to have a higher contamination with those microorganisms than those from community donors. Conclusions: The majority of DHM samples in Da Nang passed microbiological testing criteria. DHM from community donors had higher pass rates than hospital donors. Corrective actions are needed to improve HMB operations and hospital microbiological quality standards, as well as general improvements in water and sanitation.

Encapsulation of Vitamin E in Yogurt-Based Beverage Emulsions: Influence of Bulk Pasteurization and Chilled Storage on Physicochemical Stability and Starter Culture Viability.

Yogurt is a nutritious food that is regularly consumed in many countries around the world and is widely appreciated for its organoleptic properties. Despite its contribution to human dietary requirements, yogurt in its traditional recipe is a poor source of fat-soluble vitamins. To respond to consumer demands and further increase the nutritional value of this product, this work aimed to fortify yogurt with vitamin E by using emulsification as the method of encapsulation. The effects of thermal processing and chilled storage on the physicochemical stability of the yogurt-based beverage was investigated. Vitamin E was only minorly affected by bulk pasteurization at 63 °C for 30 min and remained stable during storage at 4 °C for 28 days. Fortified samples showed increased in vitro antioxidant activity compared with non-fortified samples. Lactic acid bacterial counts were above the minimum recommended levels (>106 cfu/g) after processing and storage. In conclusion, this work has demonstrated that emulsification can be an effective strategy for developing yogurt-based products fortified with fat soluble vitamins.

Green tea extract assisted low-temperature pasteurization to inactivate enteric viruses in juices.

The current popularity of minimally processed foods is an opportunity for natural antimicrobial agents to be combined with mild heat treatments to act synergistically in reducing viral foodborne pathogens. Viral inactivation by heat-treatments (at 25, 40, 50 and 63 °C for 30 min) combined with aged green tea extract (aged-GTE) was initially evaluated in phosphate buffered saline (PBS) against murine norovirus (MNV-1) and hepatitis A virus (HAV) by cell culture, and against human norovirus by in situ capture RT-qPCR. The combination of aged-GTE and heat treatment at 50 °C for 30 min exerted strong antiviral activity, reducing by more than 5 log MNV-1 infectivity in PBS. Heating at 40 °C for 30 min reduced the binding of norovirus to porcine gastric mucine (PGM) to 41.5% and the addition of aged-GTE further decreased the binding to 4.7%. Additionally, the reduction of MNV-1 and HAV infectivity was investigated in two different types of juices exposed to mild heat treatments alone, and combined with aged-GTE. The addition of aged-GTE increased to more than 4 log the inactivation of MNV-1 in juices exposed to 50 °C for 30 min. However, this synergistic effect of aged-GTE combined with heat treatments was not observed for HAV in any of the juices. Aged-GTE, then, could be considered as an additional control measure to improve the food safety of mild heat pasteurized juices.

Stability of vitamin C, color, and garlic aroma of garlic mashed potatoes in polymer packages processed with microwave-assisted thermal sterilization technology.

The U.S. Army and NASA need ready-to-eat meals with extended shelf-life for military operations and future manned space missions. For traditional heat sterilization methods, aluminum foil laminated pouches are used to achieve a shelf-life of 3 to 5 years at room temperature. However, those packages are not suited for advanced thermal processing technologies based on microwave energy. This research investigated the effect of polymeric packaging materials on storage stability of garlic flavor, vitamin C, and color of garlic mashed potatoes processed with microwave-assisted thermal sterilization (MATS) technology. Three types of high-barrier metal oxide-coated polymer pouches were used for MATS process, designed to achieve lethality approximately F0 = 6 min. Aluminum foil-based pouches were used for retort process as control. Results demonstrated that both oxygen and water vapor barrier properties (oxygen transmission rate [OTR] and water vapor transmission rate [WVTR]) of the polymer pouches were affected by MATS processing. OTR increased by three to nine times, while WVTR increased by 5 to 20 times after processing. The MATS process resulted in 13% to 16% vitamin C loss, while retort process resulted in 18% loss in garlic mashed potato. The kinetics of vitamin C indicated that metal oxide-coated high-barrier packages (after processing OTR <0.1 cc/m2 .day; WVTR <1.0 g/m2 .day) could replace aluminum foil-based pouches for MATS processed shelf-stable ready-to-eat garlic mashed potatoes. PRACTICAL APPLICATION: Garlic mashed potatoes in polymer packages processed in a microwave-assisted thermal sterilization (MATS) system had better retention of vitamin C compared to samples packaged in aluminum laminated pouches and processed in retort. Polymer packages combined with MATS processing could potentially provide safe, better quality, and nutritious shelf-stable food products for military and space missions.

Effect of pilot-scale UV-C light treatment assisted by mild heat on E. coli, L. plantarum and S. cerevisiae inactivation in clear and turbid fruit juices. Storage study of surviving populations.

Consumer growing demands for high-quality and safe food and beverages have stimulated the interest in alternative preservation technologies. Short-wavelength ultraviolet light (UV-C, 254 nm) has proven to be useful for the decontamination of a great variety of clear juices while improving their quality compared to traditional thermal treatments. Suspended solids and coloured compounds in turbid juices, diminish light transmission. The use of UV-C under a hurdle approach, may be a promising strategy for their treatment. The purpose of this study was to analyse Escherichia coli ATCC 25922, Saccharomyces cerevisiae KE 162 and Lactobacillus plantarum ATCC 8014 inactivation in clear pear juice (PJ), turbid orange-tangerine (OT) and orange-banana-mango-kiwi-strawberry (OBMKS) juices processed by single UV-C (390 mJ/cm2, 20 °C) and UV-C assisted by mild heat (UV-C/H, 50 °C) at pilot-scale in a coiled tubing unit and stored under refrigeration (5 °C). Inactivation studies were also conducted in peptone water (PW) and model solution (MS). The adequacy of the Coroller, Weibull and Biphasic Plus Shoulder models was studied. UV-C was highly effective in PW, MS and PJ, achieving up to 5.5-6.3-4.7, 4.8-5.1-4.6 and 4.4-5.5 log reductions for L. plantarum, E. coli,and S. cerevisiae, respectively. Whereas, a moderate inactivation by single UV-C was recorded in the turbid blends, reducing up to 2.4-3.8-1.6 and 3.6-3.7-1.3 log-cycles in OT and OBMKS, respectively. When the UV-C/H treatment was applied, high bacterial inactivation was observed achieving 5.2-5.6, 6.3-6.6 and 5.5-6.7 log reductions in OT, OBMKS and PJ, respectively, while 4.6-4.9 log reductions were determined for the yeast in OBMKS and OT, respectively. Thus, additive inactivation effects between UV-C and H were observed. All the models tested gave useful information regarding the existence of microbial subpopulations with varying resistances. However, the cumulative Weibull distribution function was the most versatile one, fitting inactivation curves with different shapes. Additionally, the frequency distributions of resistances showed that UV-C/H not only increased the UV-C microbicidal effect but changed the distribution of inactivation times. Principal component analysis revealed that UV-C effectiveness was associated to low particle size, a⃰, turbidity and high UV-C transmittance. An increase on the inactivation of treated bacterial populations was recorded along storage, while no yeast recovery was observed, thus emphasizing the contribution of refrigerated storage to microbial inactivation. Microbial inactivation in clear and turbid juices achieved by UV-C (390 mJ/cm2) assisted by mild heat (50 °C) and subsequent refrigerated storage may represent an useful alternative for multiple applications in the juice industry.

Combined treatment of ß-resorcylic acid and capric acid enhances mild heat pasteurization for inactivating Salmonella Typhimurium in orange juice.

This study aimed to develop a pasteurization method against Salmonella enterica serovar Typhimurium in orange juice using low concentrations of naturally derived antimicrobials, ß-resorcylic acid and capric acid, under mild temperature conditions based on their synergistic bactericidal interactions. Response surface methodology was used to construct a model based on four variables, namely ß-resorcylic acid (1, 3, 5, 7, and 9 mM), capric acid (0.05, 0.10, 0.15, 0.20, and 0.25 mM), treatment temperature (35, 40, 45, 50, and 55 °C), and time (1, 2, 3, 4, and 5 min), and the resulting model was used to predict the reduction in the content of fastidious bacteria (S. Typhimurium) in orange juice and to identify the optimal treatment combination for juice pasteurization. A second-order quadratic model for Salmonella reduction showed a high regression coefficient (R2 = 0.9503), and the accuracy of the predictive model was also verified (R2 = 0.9317). The optimal conditions determined by ridge analysis were 8.43 mM ß-resorcylic acid combined with 0.10 mM capric acid at 43.46 °C for 3.03 min, and these yielded an estimated 7.41-log reduction. Treatment times <30 s under the optimal conditions also resulted in a >5.7-log reduction. The combined treatment did not affect either the pH or sugar concentration in brix, and average pH and sugar concentration values of 3.86 and 11.05% were observed, respectively. The distinct advantage of the developed method is its ability to effectively reduce the content of S. Typhimurium over a short time under low temperature conditions through the addition of consumer-preferred naturally derived antimicrobials. The predictive model could be used to determine the most cost-efficient amounts of antimicrobial agents and conditions (treatment temperature and time) for sterilizing orange juice.

Bioactive proteins in bovine colostrum and effects of heating, drying and irradiation.

Bovine colostrum (BC) contains bioactive proteins, such as immunoglobulin G (IgG), lactoferrin (LF) and lactoperoxidase (LP). BC was subjected to low-temperature, long-time pasteurization (LTLT, 63 °C, 30 min) or high-temperature, short-time pasteurization (HTST, 72 °C, 15 s) and spray-drying (SD), with or without γ-irradiation (GI, ∼14 kGy) to remove microbial contamination. Relative to unpasteurized liquid BC, SD plus GI increased protein denaturation by 6 and 11%, respectively, increasing to 19 and 27% after LTLT and to 48% after HTST, with no further effects after GI (all P < 0.05). LTLT, without or with GI, resulted in 15 or 29% denaturation of IgG, compared with non-pasteurized BC, and 34 or 58% for HTST treatment (all P < 0.05, except LTLT without GI). For IgG, only GI, not SD or LTLT, increased denaturation (30-38%, P < 0.05) but HTST increased denaturation to 40%, with further increases after GI (60%, P < 0.05). LTLT and HTST reduced LP levels (56 and 81% respectively) and LTLT reduced LF levels (21%), especially together with GI (47%, P < 0.05). Denaturation of BSA, ß-LgA, ß-LgB and α-La were similar to IgG. Methionine, a protective amino acid against free oxygen radicals, was oxidised by LTLT + GI (P < 0.05) while LTLT and HTST had no effect. Many anti-inflammatory proteins, including serpin anti-proteinases were highly sensitive to HTST and GI but preserved after LTLT pasteurization. LTLT, followed by SD is an optimal processing technique preserving bioactive proteins when powdered BC is used as a diet supplement for sensitive patients.

Efficacy of dairy on-farm high-temperature, short-time pasteurization of milk on the viability of Mycobacterium avium ssp. paratuberculosis.

Feeding pasteurized milk to suckling calves is a popular practice used increasingly on dairy farms. Waste milk is frequently fed to calves because of its high nutritional value and economic benefits compared to milk replacement products. However, one of the disadvantages of feeding waste milk is the potential for exposure to a high number of bacterial contaminants, which may lead to serious illnesses or infections in calves. One of these contaminants is Mycobacterium avium ssp. paratuberculosis (MAP), the causative agent of Johne's disease (paratuberculosis). The transmission and distribution of paratuberculosis in dairy herds occurs mostly through the feeding newborn calves with contaminated colostrum or milk, because this age group is believed to be most susceptible to infection. To reduce the risk of transmission of pathogens, on-farm pasteurization of milk has become increasingly popular. In this study, we analyzed the efficacy of a new commercial high-temperature, short-time pasteurizer (73.5°C for 20 to 25 s) in terms of MAP inactivation under experimental on-farm conditions. The pasteurizer uses a newly developed steam-heating technique, allowing for the pasteurization of the transition milk without clumping. In 3 independent trials, we spiked fresh raw milk samples to a level of 107 or 104 viable MAP cells/mL before pasteurization. We examined the thermal inactivation and viability of MAP using culture and a D29 bacteriophage-based assay. To verify the identity and number of MAP cells, we also performed PCR assays. Pasteurization of the inoculated milk (107 and 104 MAP cells/mL) resulted in a remarkable reduction in viable MAP cells. The mean inactivation rate of MAP ranged from 0.82 to 2.65 log10 plaque-forming units/mL, depending on the initial MAP amount inoculated and the addition of conservative agents to the pasteurized milk. Nevertheless, approximately 103 MAP cells/mL remained viable and could be transferred to calves after high-temperature, short-time pasteurization of milk.

High Hydrostatic Pressure Processing Better Preserves the Nutrient and Bioactive Compound Composition of Human Donor Milk.

BACKGROUND: When mother's milk is insufficient, pasteurized human donor milk (DM) is the recommended supplement for hospitalized very-low-birth-weight infants. The current method of pasteurization (Holder, 62.5°C, 30 min) negatively affects heat-sensitive nutrients and bioactive proteins. OBJECTIVES: Objectives of this study were to compare changes in DM composition after thermal pasteurization (Holder and flash-heating) and nonthermal methods [UV-C irradiation and high hydrostatic pressure (HHP)]. We hypothesized that nonthermal techniques would result in fewer changes to composition. METHODS: Holder, flash-heating (brought to boil), UV-C irradiation (250 nm, 25 min), and HHP (500 MPa, 8 min) were studied. Pools of milk from 17 women known to contain bacteria at >5 × 107 colony forming units (CFU)/L were collected from the Rogers Hixon Ontario Human Milk Bank and underwent each pasteurization technique. Macronutrients, heat-sensitive micronutrients (vitamin C, folate), and bioactive components [bile-salt-stimulated lipase (BSSL), lysozyme, lactoferrin] were measured in raw and pools of pasteurized milk. Milk was cultured to determine how well each technique produced a culture negative result (detection limit <1 × 103 CFU/L). RESULTS: Folate was reduced by 24-27% after Holder, flash-heating, and UV-C (P < 0.05); no reduction was observed after HHP. All pasteurization methods reduced vitamin C (60-75%, P < 0.001). BSSL was abolished after Holder and flash-heating (P < 0.001), reduced after UV-C (48%, P < 0.001), but unaffected by HHP. Lysozyme activity was reduced after flash-heating (44%) and UV-C (74%, P < 0.004) but unaffected by Holder or HHP. Lactoferrin was reduced by all methods (P < 0.02) but most severely by flash-heating (74%) and least severely by HHP (25%). Holder and UV-C reduced lactoferrin by ∼48%. All pasteurization methods reduced the number of culture positive DM samples (P < 0.001). CONCLUSIONS: HHP better preserves human milk composition than Holder pasteurization. Future research on the feasibility of HHP for pasteurizing human milk is warranted because its implementation may improve the nutritional status and health of DM-fed infants.

Effects of infrared radiation combined with heating on grape seeds and oil quality.

The objective of this work was to determine the effects of infrared radiation combined with heating on grape seeds and oil quality. Experimental results showed that high moisture removal was achieved through infrared radiation heating. After infrared radiation heating for 108 s, the inactivation rates of total aerobic bacterial and total mold-yeast counts of the grape seeds were 1.97 ± 0.12 and 0.62 ± 0.09 log CFU/g, respectively. The maximum microbial reduction was achieved after infrared radiation heating of the grape seeds to 135 ℃ and subsequent holding at 75 ℃ for 60 min. The crude oil yield of samples subjected to these conditions was 10.39%, which was significantly higher ( p < 0.05) than that of the control sample, and their final moisture content was 7.20%. Additionally, increases in the free fatty acid content and peroxide value of the oil were achieved. The iodine value of the oil decreased. In conclusion, surface pasteurization with a high oil yield could be achieved by the combination of infrared radiation heating and the holding process. Consequently, infrared radiation treatment is suggested to be a promising method for the surface pasteurization of grape seeds.

Identifying possible non-thermal effects of radio frequency energy on inactivating food microorganisms.

Radio frequency (RF) heating has been successfully used for inactivating microorganisms in agricultural and food products. Athermal (non-thermal) effects of RF energy on microorganisms have been frequently proposed in the literature, resulting in difficulties for developing effective thermal treatment protocols. The purpose of this study was to identify if the athermal inactivation of microorganisms existed during RF treatments. Escherichia coli and Staphylococcus aureus in apple juice and mashed potato were exposed to both RF and conventional thermal energies to compare their inactivation populations. A thermal death time (TDT) heating block system was used as conventional thermal energy source to simulate the same heating treatment conditions, involving heating temperature, heating rate and uniformity, of a RF treatment at a frequency of 27.12 MHz. Results showed that a similar and uniform temperature distribution in tested samples was achieved in both heating systems, so that the central sample temperature could be used as representative one for evaluating thermal inactivation of microorganisms. The survival patterns of two target microorganisms in two food samples were similar both for RF and heating block treatments since their absolute difference of survival populations was <1 log CFU/ml. The statistical analysis indicated no significant difference (P > 0.05) in inactivating bacteria between the RF and the heating block treatments at each set of temperatures. The solid temperature and microbial inactivation data demonstrated that only thermal effect of RF energy at 27.12 MHz was observed on inactivating microorganisms in foods.

Antibody Profile of Colostrum and the Effect of Processing in Human Milk Banks: Implications in Immunoregulatory Properties.

BACKGROUND: When feeding preterm infants, donor milk is preferred if the mother's own milk is unavailable. Pasteurization may have detrimental effects on bioactivity, but more information is needed about its effects on the immunological compounds. Research aim: This work has two main aims: evaluate the antibody profile of colostrum and study the quantitative variations in the antibodies' level and specific reactivity after undergoing Holder pasteurization. The authors focused on immunoregulatory components of colostrum (antidietary antibodies and TGF-ß2) in the neonatal gut. METHODS: This is a descriptive cross-sectional study of a convenience sample of 67 donated colostrum samples at different days after delivery, both raw and pasteurized. Antibody profiles were analyzed at different times during breastfeeding, and total and specific antibodies (IgM, IgA, and IgG subclasses) were compared with tetanus toxoid and ovalbumin using enzyme-linked immunosorbent assay. The processing effect on total and specific antibodies, as well as TGF-ß2, was evaluated by paired analyses. RESULTS: No variations in immunological compounds were observed throughout the colostrum stage. The TGF-ß2, antibodies' concentrations, and antibodies' specific reactivity after pasteurization did not vary significantly as days of lactation varied. Changes in antibody levels were dependent on isotype and IgG subclass, and IgG4 showed remarkable resistance to heating. Moreover, the effect of the pasteurization on specific reactivity was antigen dependent. CONCLUSION: The supply of relevant immunological components is stable throughout the colostrum stage. The effects of pasteurization on antibodies depend on isotype, subclass, and specificity. This information is relevant to improving the immunological quality of colostrum, especially for preterm newborns.

Effect of medicinal plants, Heavy metals and antibiotics against pathogenic bacteria isolated from raw, Boiled and pasteurized milk.

Present study has been undertaken to isolate and identify the bacterial flora in raw, boiled and pasteurized milk. Agar disc diffusion method was used to determine their sensitivity using medicinal plants, antibiotics and heavy metals. Methylene blue reduction test was used to test the quality of milk samples. Total 10 pathogenic strains were isolated, five strains were isolated from raw milk, three from boiled milk and 2 two from pasteurized milk. To determine optimum conditions for growth, these pathogenic microorganisms were incubated at various temperatures and pH. Gram's staining and biochemical tests revealed that these pathogenic bacteria include Lactobacillus sp., E. coli, Salmonella sp., Pseudomonas sp., Streptococcus sp. and Staphylococcus. Ribotyping revealed S2 as Pseudomonas fluorescens, S5 as Lactococcus lactis and S9 as Lactobacillus acidophilus. Prevalence of pathogenic organisms provided the evidence that contamination of milk arises during milking, transportation and storage of milk. Raw milk is more contaminated than other two types of milk because it contains highest percentage of pathogenic organisms and pasteurized milk was found to be of best quality among three types. So it is recommended to drink milk after proper boiling or pasteurization. Proper pasteurization and hygienic packing of milk is essential to minimize contamination in milk which can save human beings from many milk borne diseases. Our study suggests that antimicrobial use in animal husbandry should be minimized to reduce the hazard of antibiotic resistance. Plant extracts are better alternative against pathogenic bacteria in milk.

Verification of radio frequency pasteurization treatment for controlling Aspergillus parasiticus on corn grains.

Radio frequency (RF) heating has been proposed and tested to achieve a required anti-fungal efficacy on various food samples due to its advantage of deeper penetration depth and better heating uniformity. The purpose of this study was to validate applications of RF treatments for controlling Aspergillus parasiticus in corn while maintaining product quality. A pilot-scale, 27.12MHz, 6kW RF heating system together with hot air heating was used to rapidly pasteurize 3.0kg corn samples. Results showed that the pasteurizing effect of RF heating on Aspergillus parasiticus increased with increasing heating temperature and holding time, and RF heating at 70°C holding in hot air for at least 12min resulted in 5-6 log reduction of Aspergillus parasiticus in corn samples with the moisture content of 15.0% w.b. Furthermore, thermal resistance of Aspergillus parasiticus decreased with increasing moisture content (MC) of corn samples. Quality (MC, water activity - aw, protein, starch, ash, fat, fatty acid, color, electrical conductivity and germination rate) of RF treated corn met the required quality standard used in cereal industry. Therefore, RF treatments can provide an effective and rapid heating method to control Aspergillus parasiticus and maintain acceptable corn quality.

Evaluation of human milk titratable acidity before and after addition of a nutritional supplement for preterm newborns / Avaliação da acidez titulável do leite humano antes e após adição de um suplemento nutricional para recém-nascido pré-termo

Abstract Objective: To evaluate the initial Dornic acidity in raw human milk, after pasteurization and after heating and dilution of a dietary supplement for preterm infants. Methods: A quantitative, descriptive, and experimental study was carried out with a convenience sample at the human milk bank at a Brazilian public maternity, with specialized care for pregnant women and newborns at risk. The eligibility criteria for the study sample included 93 frozen raw human milk in suitable containers with volumes ≥100 mL and initial Dornic acidity ≤8° Dornic (ºD). Milk acidity of human milk was measured in four stages: in raw human milk (initial); after pasteurization; after the heating of pasteurized milk and dilution of the supplement; and after thirty minutes of supplementation. Results: The initial acidity was 3.8° D ± 1.3 (95% CI: 3.56-4.09) with no significant difference in Dornic acidity in pasteurized milk, which was 3.6° D ± 1.2 (95% CI: 3.36-3.87). The dilution of the supplement in pasteurized milk that was heated significantly increased mean Dornic acidity to 18.6 °D ± 2.2 (95% CI: 18.18-19.11), which remained high after thirty minutes of supplementation at 17.8 °D ± 2.2 (95% CI: 17.36-18.27), considering p < 0.05. Conclusions: The study observed no significant differences in Dornic acidity of raw human milk and pasteurized human milk; however, the dilution of a human milk supplementation caused a significant increase in acidity. Further investigations are necessary on the influence of this finding on the quality of supplemented milk and its consequences on the health of preterm infants.

Resumo Objetivo Avaliar a acidez Dornic inicial no leite humano cru, após pasteurização, e aquecimento e diluição de um suplemento nutricional para recém-nascidos prematuros. Métodos Estudo quantitativo, descritivo, experimental, com amostragem por conveniência, feito no Banco de Leite Humano de uma maternidade pública brasileira, com assistência especializada às gestantes e recém-nascidos de risco. Os critérios de elegibilidade das 93 amostras do estudo incluíram leites humanos crus congelados em embalagens apropriadas, com volumes ≥ 100 mL e acidez Dornic inicial ≤ 8°Dornic (°D). A acidez Dornic dos leites humanos foi mensurada em quatro momentos: no leite humano cru (inicial); após pasteurização; após aquecimento do leite pasteurizado e diluição do suplemento; e após transcorridos 30 minutos de suplementação. Resultados A acidez inicial foi de 3,8°D ± 1,3 (IC 3,56-4,09) e não apresentou diferença significativa em relação à acidez Dornic no leite pasteurizado, que foi de 3,6°D ± 1,2 (IC 3,36-3,87). A diluição do suplemento no leite pasteurizado e aquecido aumentou significativamente a média da acidez Dornic a 18,6°D ± 2,2 (IC 18,18-19,11), a qual se manteve elevada em 17,8°D ± 2,2 (IC 17,36-18,27) após 30 minutos da diluição, considerando p < 0,05. Conclusões O estudo demonstrou que a acidez Dornic do leite humano cru e a do leite humano pasteurizado não apresentaram diferenças significativas, porém a diluição do suplemento de leite humano promoveu elevação significativa da acidez. Maiores investigações da influência desse achado sobre a qualidade do leite suplementado e suas consequências na saúde de prematuros são necessárias.

Evaluation of human milk titratable acidity before and after addition of a nutritional supplement for preterm newborns.

OBJECTIVE: To evaluate the initial Dornic acidity in raw human milk, after pasteurization and after heating and dilution of a dietary supplement for preterm infants. METHODS: A quantitative, descriptive, and experimental study was carried out with a convenience sample at the human milk bank at a Brazilian public maternity, with specialized care for pregnant women and newborns at risk. The eligibility criteria for the study sample included 93 frozen raw human milk in suitable containers with volumes ≥100mL and initial Dornic acidity ≤8° Dornic (°D). Milk acidity of human milk was measured in four stages: in raw human milk (initial); after pasteurization; after the heating of pasteurized milk and dilution of the supplement; and after thirty minutes of supplementation. RESULTS: The initial acidity was 3.8°D±1.3 (95% CI: 3.56-4.09) with no significant difference in Dornic acidity in pasteurized milk, which was 3.6°D±1.2 (95% CI: 3.36-3.87). The dilution of the supplement in pasteurized milk that was heated significantly increased mean Dornic acidity to 18.6°D±2.2 (95% CI: 18.18-19.11), which remained high after thirty minutes of supplementation at 17.8°D±2.2 (95% CI: 17.36-18.27), considering p<0.05. CONCLUSIONS: The study observed no significant differences in Dornic acidity of raw human milk and pasteurized human milk; however, the dilution of a human milk supplementation caused a significant increase in acidity. Further investigations are necessary on the influence of this finding on the quality of supplemented milk and its consequences on the health of preterm infants.

Antioxidative Activity of Colostrum and Human Milk: Effects of Pasteurization and Storage.

OBJECTIVES: Milk banks collect, pasteurize, and freeze/store human milk. The processing may alter redox properties of milk, but the effects have not been fully examined. METHODS: We collected 10 mature milk and 10 colostrum samples and applied a battery of biochemical assays and electron paramagnetic resonance spectroscopy to inspect changes that milk undergoes with pasteurization and 30 days storage at -20°C. RESULTS: Pasteurization and storage of raw milk did not affect total nonenzymatic antioxidative capacity, but specific components and features were altered. Urate radical and ascorbyl radical emerge as products of exposure of milk to hydroxyl radical-generating system. Processing shifted the load of antioxidative activity from ascorbate to urate and lowered the capacity of milk to diminish hydroxyl radical. Pasteurization caused a significant drop in the activity of 2 major antioxidative enzymes-superoxide dismutase and glutathione peroxidase, whereas freezing/storage of raw milk affected only superoxide dismutase. Colostrum showed drastically higher total nonenzymatic antioxidative capacity, hydroxyl radical scavenging ability, and glutathione reductase activity compared with mature milk. CONCLUSIONS: Pasteurization and storage affect nonenzymatic and enzymatic antioxidative agents in human milk. It appears that nonenzymatic antioxidative systems in colostrum and milk are different. The effects of processing may be partially compensated by fortification/spiking with ascorbate before use.

Response Surface Optimization of Process Parameters and Fuzzy Analysis of Sensory Data of High Pressure-Temperature Treated Pineapple Puree.

The high-pressure processing conditions were optimized for pineapple puree within the domain of 400-600 MPa, 40-60 °C, and 10-20 min using the response surface methodology (RSM). The target was to maximize the inactivation of polyphenoloxidase (PPO) along with a minimal loss in beneficial bromelain (BRM) activity, ascorbic acid (AA) content, antioxidant capacity, and color in the sample. The optimum condition was 600 MPa, 50 °C, and 13 min, having the highest desirability of 0.604, which resulted in 44% PPO and 47% BRM activities. However, 93% antioxidant activity and 85% AA were retained in optimized sample with a total color change (∆E*) value less than 2.5. A 10-fold reduction in PPO activity was obtained at 600 MPa/70 °C/20 min; however, the thermal degradation of nutrients was severe at this condition. Fuzzy mathematical approach confirmed that sensory acceptance of the optimized sample was close to the fresh sample; whereas, the thermally pasteurized sample (treated at 0.1 MPa, 95 °C for 12 min) had the least sensory score as compared to others.

Effect of feeding heat-treated colostrum on risk for infection with Mycobacterium avium ssp. paratuberculosis, milk production, and longevity in Holstein dairy cows.

In summer 2007, a randomized controlled field trial was initiated on 6 large Midwest commercial dairy farms to investigate the effect of feeding heat-treated (HT) colostrum on transmission of Mycobacterium avium ssp. paratuberculosis (MAP) and on future milk production and longevity within the herd. On each farm, colostrum was collected daily from fresh cows, pooled, divided into 2 aliquots, and then 1 aliquot was heat-treated in a commercial batch pasteurizer at 60°C for 60min. A sample from each batch of colostrum was collected for PCR testing (MAP-positive vs. MAP-negative). Newborn heifer calves were removed from the dam within 30 to 60min of birth and systematically assigned to be fed 3.8 L of either fresh (FR; n=434) or heat-treated (HT; n=490) colostrum within 2h of birth. After reaching adulthood (>2 yr old), study animals were tested once annually for 3 yr (2010, 2011, 2012) for infection with MAP using serum ELISA and fecal culture. Lactation records describing milk production data and death or culling events were collected during the 3-yr testing period. Multivariable model logistic and linear regression was used to investigate the effect of feeding HT colostrum on risk for testing positive to MAP during the 3-yr testing period (positive/negative; logistic regression) and on first and second lactation milk yield (kg/cow; linear regression), respectively. Cox proportional hazards regression was used to investigate the effect of feeding HT colostrum on risk and time to removal from the herd. Fifteen percent of all study animals were fed PCR-positive colostrum. By the end of the 3-yr testing period, no difference was noted in the proportion of animals testing positive for MAP, with either serum ELISA or fecal culture, when comparing the HT group (10.5%) versus the FR group (8.1%). There was no effect of treatment on first- (HT=11.797kg; FR=11,671kg) or second-lactation (HT=11,013kg; FR=11,235kg) milk production. The proportion of cows leaving the herd by study conclusion was not different for animals originally fed HT (68.0%) versus FR (71.7%) colostrum. Although a previous study showed that feeding HT colostrum (60°C for 60min) produces short-term benefits, including improved passive transfer of IgG and reduced morbidity in the preweaning period, the current study found no benefit of feeding HT colostrum on long-term outcomes including risk for transmission of Mycobacterium avium ssp. paratuberculosis, milk production in the first and second lactation, and longevity within the herd.

Volatile profile of breast milk subjected to high-pressure processing or thermal treatment.

The effect of Holder pasteurisation (HoP) (62.5°C for 30 min) or high-pressure treatments (400 or 600 MPa for 3 or 6 min) on the volatile compound profile of human breast milk was evaluated, in order to compare both preservation technologies. A total of 46 different volatile compounds was found in milk samples. The most abundant compounds detected were aliphatic hydrocarbons. In general, the effect of some high-pressure treatments on the volatile profile of human milk was less intense than that caused by HoP. The treatments at 400 and 600 MPa for 3 min maintained the volatile compounds at similar levels to those found in control milk samples. However, the application of 600 MPa for 6 min changed the original volatile compounds of human milk, even more than HoP. Since, HPP at 400 or 600 MPa for 3 min preserved the original volatile compounds of human milk, this novel process may be an alternative to thermal pasteurisation.