Production of Low Lactose and Low Serum Protein Milk Protein Beverage by Microfiltration.

Our objective was to determine the impact of simultaneous removal of lactose plus low molecular weight solutes and milk serum proteins from skim milk by microfiltration (MF) on the chemical, physical and sensory properties of 3.4, 7.5, and 10.5% milk protein-based beverages before and after a direct steam injection thermal process. Skim milk was microfiltered at 50°C using 0.1 micron ceramic membranes with a diafiltration ratio of water to milk of about 2.5. Milk lactose, serum proteins, and soluble minerals were removed simultaneously to produce protein beverages containing from 3.4 to 10.5% true protein from skim milk and this process was replicated twice with different skim milks. The soluble mineral plus lactose content was very low and the aqueous phase of the beverages had a freezing point very close to water (i.e., -0.02°C). Beverage pH ranged from 7.19 to 7.41, with pH decreasing with increasing protein concentration. Overall, the beverages were whiter and blander than skim milk. When UHT processed with direct steam injection at a holding temp of 140°C for 2 to 3 s, there was some protein aggregation detected by particle size analysis (volume mean diameter of protein particles was 0.16 micron before and 22 microns after UHT). No sulfur/eggy flavor was detected and no browning was observed due to the UHT thermal treatment. Both apparent viscosity and sensory viscosity increased with increasing protein concentration and heat treatment.

Recent advances on lactose intolerance: Tolerance thresholds and currently available answers.

The genetically programmed reduction in lactase activity during adulthood affects 70% of the world adult population and can cause severe digestive disorders, which are the sign of lactose intolerance. Lactose intolerance symptoms vary depending on the residual lactase activity, the small bowel transit time, and especially the amount of ingested lactose. To formulate dairy products suitable for the vast majority of lactose intolerants, it is essential to define lactose intolerance threshold. A recent meta-analysis permitted to show that almost all lactose intolerants tolerate 12 g of lactose in one intake and approximately 18 g of lactose spread over the day. The prevalence and severity of lactose intolerance are probably overestimated by the general public. This misconception usually leads to an unnecessary reduction of dairy foodstuff consumption. Nevertheless, dairy products are essential for health mainly due to their calcium content and the positive influence of probiotic bacteria. The formulation of dairy products suitable for most intolerant and suspicious subjects seems necessary. The use of exogenous enzyme preparations, as well as the consumption of lactose-free products or products rich in probiotic bacteria are proposed as symptom-reducing strategies.

Milk protein-based infant formula containing rice starch and low lactose reduces common regurgitation in healthy term infants: a randomized, blinded, and prospective trial.

OBJECTIVE: Spit-up (regurgitation) reduction with prethickened milk protein-based infant formulas containing rice starch has been clinically demonstrated in infants with heavy spit-ups but not in otherwise healthy normal infants with common spit-ups. The objective of this study was to evaluate growth, gastrointestinal tolerance, and efficacy to reduce common spit-up in normal, healthy term infants fed an investigational rice starch prethickened lactose-free milk protein-based infant formula. METHODS: This double-blind, randomized, parallel study evaluated the investigational rice starch prethickened lactose-free (low lactose < 100 mg/L) milk protein-based infant formula compared to a standard, commercially available, iso-nutrient, lactose-containing (100% of carbohydrate) milk-based infant formula (control) for growth and gastrointestinal tolerance in healthy term infants (n = 132/group) fed from 14 ± 3 days to 112 days of age. Data were classified and analyzed as evaluable (EV; subjects completing study per protocol) or intent-to-treat data (ITT; all subjects with available data). RESULTS: Growth as indicated by weight gain (primary variable) and formula intake were not significantly different (p > 0.05) between feeding groups (EV or ITT). Though both formulas were well tolerated, spit-up frequency was significantly lower (p < 0.05) in the rice versus control group by 53% at 28 days of age, 54% at 56 days, 48% at 84 days, and 32% at 112 days (EV). Importantly, infants in the rice group were 1.6 to 1.8 times more likely to report zero spit-up than infants in the control group. The rice group also had higher percentages of soft and yellow stools. CONCLUSIONS: The rice starch prethickened lactose-free milk protein-based formula (rice) supported normal growth and safe use as the sole source of feeding for normal infants over the first 4 months of life. The rice formula was efficacious in providing a clinically relevant reduction of spit-up frequency in otherwise healthy term infants.

Reduction of maillard browning in spray dried low-lactose milk powders due to protein polysaccharide interactions.

Lactose hydrolysed concentrated milk was prepared using ß-galactosidase enzyme (4.76U/mL) with a reaction period of 12 h at 4 °C. Addition of polysaccharides (5 % maltodextrin/ß-cyclodextrin) to concentrated milk either before or after lactose hydrolysis did not result in significant differences (p > 0.05) in degree of hydrolysis (% DH) of lactose and residual lactose content (%). Three different inlet temperatures (165 °C, 175 °C and 185 °C) were used for the preparation of powders which were later characterised based on physico-chemical and maillard browning characteristics. Moisture content, solubility and available lysine content of the powders decreased significantly, whereas, browning parameters i.e., browning index, 5-hydroxymethylfurfural, furosine content increased significantly (p < 0.05) with an increase in inlet air temperature. The powder was finally prepared with 5 % polysaccharide and an inlet air temperature of 185 °C which reduced maillard browning. Protein-polysaccharide interactions were identified using Fourier Transform infrared spectroscopy, fluorescence spectroscopy and determination of free amino groups in the powder samples. Maltodextrin and ß-cyclodextrin containing powder samples exhibited lower free amino groups and higher degree of graft value as compared to control sample which indicated protein-polysaccharide interactions. Results obtained from Fourier Transform infrared spectroscopy also confirmed strong protein-polysaccharide interactions, moreover a significant decrease in fluorescence intensity was also observed in the powder samples. These interactions between the proteins and polysaccharides reduced the maillard browning in powders.

Determination of the lactose content in low-lactose milk using Fourier-transform infrared spectroscopy (FTIR) and convolutional neural network.

Demand for low lactose milk and milk products has been increasing worldwide due to the high number of people with lactose intolerance. These low lactose dairy foods require fast, low-cost and efficient methods for sugar quantification. However, available methods do not meet all these requirements. In this work, we propose the association of FTIR (Fourier Transform Infrared) spectroscopy with artificial intelligence to identify and quantify residual lactose and other sugars in milk. Convolutional neural networks (CNN) were built from the infrared spectra without preprocessing the data using hyperparameter adjustment and saliency map. For the quantitative prediction of the sugars in milk, a regression model was proposed, while for the qualitative assessment, a classification model was used. Raw, pasteurized and ultra-high temperature (UHT) milk was added with lactose, glucose, and galactose in six concentrations (0.1-7.0 mg mL-1) and, in total, 432 samples were submitted to convolutional neural network. Accuracy, precision, sensitivity, specificity, root mean square error, mean square error, mean absolute error, and coefficient of determination (R2) were used as evaluation parameters. The algorithms indicated a predictive capacity (accuracy) above 95% for classification, and R2 of 81%, 86%, and 92% for respectively, lactose, glucose, and galactose quantification. Our results showed that the association of FTIR spectra with artificial intelligence tools, such as CNN, is an efficient, quick, and low-cost methodology for quantifying lactose and other sugars in milk.

Effect of process parameters on the ß-galactosidase hydrolysis of lactose and galactooligosaccharide formation in concentrated skim milk.

The study aimed at evaluation of ß-galactosidase activity for lactose hydrolysis (DH) and galactooligosaccharide (GOS) formation at 7 °C. ß-galactosidase derived from K. lactis was more effective than B. lichenformis for DH and GOS formation in 16% lactose solution. ß-galactosidase from K. lactis exhibited 96.61% DH and 7.28% GOS production after 12 h of reaction and hence was utilized for lactose hydrolysis in concentrated skim milk (40% total solids). Use of 9.53 U/mL enzyme resulted in significantly high DH (97.06%) after 12 h with 4.90 g/L of residual lactose. However, maximum GOS formation of 12.01% with 94.74% DH was obtained after 4 h. Further increase in reaction time up to 12 h resulted in breakdown of tri and tetrasaccharide GOS, thereby, reducing GOS content. Hence, reaction time of 12 h was finalized to obtain maximum DH along with additional benefit of GOS formation.

Rice straw and orange peel wastes as cheap and eco-friendly substrates: A new approach in ß-galactosidase (lactase) enzyme production by the new isolate L. paracasei MK852178 to produce low-lactose yogurt for lactose-intolerant people.

Converting wastes to valuable products is the main target for many kinds of research nowadays. Wastes represent an environmental problem and getting rid of it is not easy and causes pollution. Accordingly, this study offers production of the valuable enzyme ß-galactosidase using rice straw and orange peel as the main medium constituents. ß-galactosidase converts lactose to glucose and galactose which are simple sugars and can be fermented easily by lactose-intolerant people who represent more than 50% of the world's population. It was produced by Lactobacillus paracasei, a series isolated from fermented milk, identified using 16S ribosomal RNA gene partial sequence and had the accession number MK852178. Plackett-Burman (PB) and Central Composite (CCD) Designs optimized the production scoring 1.683(10)6 U/ml with a difference five times higher than the non-optimized medium. The addition of 0.3 or 0.6% of ß-galactosidase serves as a good fortification for manufacturing nutritional and therapeutic low-lactose yogurt with no significant differences in total protein, total solids, fat, and ash between control and all treatments. The chemical, rheological and sensory properties of the final produced yogurt were evaluated during storage periods up to 9 days at 5 °C. In conclusion, L. paracasei MK852178 ß-galactosidase is a promising additive in manufacturing low lactose yogurt for lactose-intolerant people since it reduces the lactose content and doesn't influence the chemical and sensory properties.

The Effects of a Partially Hydrolyzed Formula with Low Lactose and Probiotics on Mild Gastrointestinal Disorders of Infants: A Single-Armed Clinical Trial.

Partially hydrolyzed formula (pHF) containing low lactose and probiotics may benefit the gastrointestinal health of infants. We aimed to assess the effects of pHF on mild gastrointestinal disorders (MGDs) of infants. In this single-armed trial, 80 full-term infants with MGDs were enrolled and fed a pHF for 14 consecutive days. The primary outcome resulted from the scores of gastrointestinal symptoms reported by parents using a validated Infant Gastrointestinal Symptom Questionnaire (IGSQ) at Day 0 (baseline), Day 7, and Day 14. The total IGSQ scores ranged from 13 to 65. Higher scores indicated worse gastrointestinal symptoms. The IGSQ scores (mean ± SD) decreased from Day 0 (36.0 ± 5.7) to Day 7 (28.7 ± 7.4) and Day 14 (26.5 ± 8.1 (p < 0.001), with corresponding digestive distress prevalence (IGSQ score > 30) decreasing from 87.5% to 35.0% and 28.8% (p < 0.001). In the first three days, vomiting and flatulence scores decreased at Day 1 versus Day 0, and the crying score decreased at Day 2, but no significant changes were observed for fussy and stool characteristics. All growth parameters increased and no parents reported adverse events. In conclusion, feeding with a pHF containing low lactose and probiotics may comfort infants with MGDs, and the comforting effect likely manifests early in the first three days of the feeding interventions. Trial registration: ClinicalTrials.gov NCT04112056.

Treatment efficacy of a low FODMAP diet compared to a low lactose diet in IBS patients: A randomized, cross-over designed study.

BACKGROUND AND OBJECTIVE: A low FODMAP diet (LFD) has become a standard treatment in irritable bowel syndrome (IBS) patients. Compliant adherence to a LFD is challenging. We investigated the effect of a LFD compared to a less restrictive low lactose diet (LLD) in a randomized cross-over trial with IBS patients. METHODS: Twenty-nine IBS patients were randomly assigned to two groups. After a run-in phase of 14 days, patients received 21 days of either a LFD or LLD. This intervention was followed by a washout period of 21 days before crossing over to the alternate diet. Dietician led diet instruction was given continuously. An IBS Severity Scoring System (IBS-SSS) was filled in at the end of each study period. To enhance study adherence, daily symptoms were assessed using a Visual Analog Scale (VAS). RESULTS: IBS patients, irrespective of lactase deficiency, had a significantly reduced IBS-SSS score after both diets (LFD p = 0.002, LLD p = 0.007) without significant difference. On both diets, patients reported that IBS had less impact on their daily life compared to the time before the study (p < 0.01). On daily assessment, IBS patients on LFD reported significantly less abdominal pain (median VAS difference to baseline -0.8 (-2.8 to 2.7, p = 0.03) and less bloating (-0.5 (-4.1 to 3.4, p = 0.02) than patients on the LLD. CONCLUSION: Both diets improved the overall IBS severity significantly and patients' preference of the two diets was similar. LFD but not LLD effectively reduced pain and bloating in patients with IBS.

Improving Galactooligosaccharide Synthesis Efficiency of ß-Galactosidase Bgal1-3 by Reshaping the Active Site with an Intelligent Hydrophobic Amino Acid Scanning.

There are ongoing interests in improving the galactooligosaccharide (GOS) synthesis efficiency of ß-galactosidase by protein engineering. In this study, an intelligent double-hydrophobic amino acid scanning strategy was proposed and employed to target nine residues forming the glycon-binding site (-1 subsite) of ß-galactosidase Bgal1-3. Two mutants C510V and H512I with significantly improved GOS synthesis efficiency were obtained. When 40% (w/v) lactose was used as a substrate, Bgal1-3 reached a maximum GOS yield of 45.3% at 16 h, while the mutants reached higher yields in a much shorter time (59.1% at 10 h for C510V, 51.5% at 2 h for H512I). When skim milk was treated with these enzymes, more GOS was produced (19.9 g/L for C510V, 12.7 g/L for H512I) than that for Bgal1-3 (10.3 g/L) at a lactose conversion of 90%. These results validated hydrophobicity scanning as an efficient method to engineer ß-galactosidases into promising catalysts for the preparation of GOS and GOS-enriched milk.

FT-Raman and chemometric tools for rapid determination of quality parameters in milk powder: Classification of samples for the presence of lactose and fraud detection by addition of maltodextrin.

FT-Raman spectroscopy has been explored as a quick screening method to evaluate the presence of lactose and identify milk powder samples adulterated with maltodextrin (2.5-50% w/w). Raman measurements can easily differentiate samples of milk powder, without the need for sample preparation, while traditional quality control methods, including high performance liquid chromatography, are cumbersome and slow. FT-Raman spectra were obtained from samples of whole lactose and low-lactose milk powder, both without and with addition of maltodextrin. Differences were observed between the spectra involved in identifying samples with low lactose content, as well as adulterated samples. Exploratory data analysis using Raman spectroscopy and multivariate analysis was also developed to classify samples with PCA and PLS-DA. The PLS-DA models obtained allowed to correctly classify all samples. These results demonstrate the utility of FT-Raman spectroscopy in combination with chemometrics to infer about the quality of milk powder.

The quality of low lactose milk is affected by the side proteolytic activity of the lactase used in the production process.

Lactose intolerance syndrome can be efficiently tackled consuming low lactose products. Lactase is the key tool to manufacture low lactose milk (LLM): its addition during milk processing can be done "in batch", i.e. before thermal treatment, or directly "in pack" after sterilization. In this paper data on sensory properties, Maillard Reaction products (MRPs) and free amino acids formation were obtained on six commercial Italian LLMs over six months storage. They showed that the side proteolytic activity of lactase caused the release of amino acids with a significant higher MRPs and off-flavors formation in four out of five samples produced by adding the enzyme in the pack after thermal treatment. We concluded that the in pack addition of lactase after milk sterilization can have negative sensorial and nutritional consequences mainly related to the enzyme side proteolytic activity especially for prolonged storage time.

Development of stuffed coalho cheese in the traditional, lactose-free and probiotic-added formulations / Desenvolvimento de queijo de coalho trufado nas versões tradicional, delactosado e com adição de probiótico

ABSTRACT: The probiotic products from the dairy market have been extensively exploited as well as lactose-free derivatives, suitable for lactose intolerant individuals. This research aimed to manufacture stuffed cheese with Brazilian cream cheese and spices in three versions (traditional, lactose-free, and probiotic cheese) and evaluate their quality by physico-chemical and microbiological analyses, Lactic Acid Bacteria (LAB) viability, and acceptance and preference assays. Physico-chemical properties of the formulations were all in accordance with the standards for the fat content of the Ordinance No. 146 for the traditional (54.06%) and probiotic (45.45%) full-fat samples and free-lactose (39.28%) medium-fat sample. Regarding the microbiological safety, all the samples presented to be ready for consumption, and the LAB count were still viable after 42 days of storage in the probiotic formulation at the order of 108 log CFU/mL. The lactose-free formulation achieved the highest acceptance rates among the public regarding sensorial qualities with an average grade of 7.27 out of 9. In the end, the three types of stuffed coalho cheese were successful in total quality control and also the probiotic formulation with the desired viable count after storage and lactose-free formulation with the best acceptance rates by the public.

RESUMO: A crescente consciência dos consumidores sobre a relação existente entre saúde e dieta, tem despertado o interesse por alimentos que promovem efeitos benéficos ao ser humano. Desta maneira, o mercado de produtos lácteos com alegações probióticas passou a ser bastante explorado, assim como os delactosados, adequados ao público intolerante a lactose. O objetivo deste estudo foi produzir queijo de coalho trufado com requeijão e especiarias nas versões tradicional, delactosado e com adição de probiótico, sendo realizadas análises físico-química, microbiológicas, viabilidade das bactérias ácido láticas, teste de aceitação e preferência. As características físico-químicas dos queijos produzidos permaneceram dentro dos padrões da legislação brasileira. Os queijos desenvolvidos apresentaram segurança microbiológica para consumo e as bactérias ácido láticas revelaram-se viáveis no produto por um período de 42 dias. Considerado mais uma alternativa para o público com intolerância a lactose, o queijo coalho trufado delactosado demonstrou melhor aceitação sensorial em relação as demais versões.

Evolution of protein bound Maillard reaction end-products and free Amadori compounds in low lactose milk in presence of fructosamine oxidase I.

Thermal treatments and storage influence milk quality, particularly in low lactose milk as the higher concentration of reducing sugars can lead to the increased formation of the Maillard reaction products (MRPs). The control of the Amadori products (APs) formation is the key step to mitigate the Maillard reaction (MR) in milk. The use of fructosamine oxidases, (Faox) provided promising results. In this paper, the effects of Faox I were evaluated by monitoring the concentration of free and bound MRPs in low lactose milk during shelf life. Results showed that the enzyme reduced the formation of protein-bound MRPs down to 79% after six days at 37°C. Faox I lowered the glycation of almost all the free amino acids resulting effective on basic and polar amino acids. Data here reported corroborate previous findings on the potentiality of Faox enzymes in controlling the early stage of the MR in foods.

Fermented beverage based on water-soluble soybean extract / Bebida fermentada à base de extrato hidrosolúvel de soja

Functional foods are those that, beyond basic nutrition, promote health benefits. This study aimed to produce a fermented beverage from a water-soluble soybean extract and low-lactose semi-skimmed milk. The beverage was prepared using a blend (v/v) containing 62% water-soluble soybean extract, 33% low-lactose semi-skimmed milk, and 5% of an inoculum containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus. The fermentation was carried out with monitoring of the lactic acid bacteria (LAB) counts, pH, and titrable acidity (% lactic acid). The consumption-ready fermented beverage was added of strawberry syrup and posteriorly characterized by its centesimal composition and sensory attributes as appearance, aroma, flavour, texture, overall impression, and purchase intent. Additionally, the LAB count and presence of pathogens in the final product were evaluated. After 14 h of fermentation, the refrigerated product presented L. bulgaricus and S. thermophilus counts of 8.5 × 103 and 7.4 × 107 CFU/mL, respectively. The product contained 14.93% carbohydrates, 0.76% fats, 0.96% ash, 22.76% totalsolids, and 2.19% protein. Because the product did not present any pathogens, it was adequate according to the standards of microbiological safety determined by Brazilian legislation. Regarding the sensory evaluation, the panelists assigned a mean score of 7.0 for the attributes evaluated, indicating 'liked moderately' to the drink. In addition, 61% of the evaluators responded that they 'certainly or probably would buy' the product if it were available on the market.

Alimentos funcionais são aqueles que, além da nutrição básica, promovem benefícios à saúde. Este trabalho teve como objetivo produzir uma bebida fermentada a partir de extrato hidrosolúvel de soja (EHS) e leite semidesnatado com baixa lactose. A bebida foi preparada utilizando uma mistura (v/v) contendo 62% de EHS, 33% de leite semidesnatado com baixa lactose e 5% de inóculo contendo Lactobacillus delbrueckii subsp. Bulgaricus e Streptococcus salivarius subsp. Thermophilus. A fermentação foi acompanhada durante 14 horas, através das contagens das bactérias ácido lácticas, pH e a acidez titulável (% de ácido láctico). A bebida fermentada pronta para consumo foi adicionada de uma calda de morango e caracterizada por sua composição centesimal, bem como por avaliação sensorial para os atributos: aparência, aroma, sabor, impressão global e intenção de compra. Além disso, a contagem das bactérias lácticas e presença de patógenos no produto foi avaliada. Após 14 horas de fermentação, o produto final refrigerado apresentou contagens de 8,5x103 UFC/mL e 7,4x107 UFC/mL para as bactérias L. bulgaricus e S. thermophilus respectivamente. O produto apresentou 14,93% de carboidratos, 0,76% de gordura, 0,96% de cinzas, 22,76% de sólidos totais e 2,19% de proteína. O produto não apresentou quaisquer patógenos, portanto, foi adequado aos padrões determinados pela legislação brasileira quanto à segurança microbiólogica. Com relação à avaliação sensorial, os provadores atribuíram em média nota 7,0 para todos os parâmetros avaliados, indicando que "gostarammoderadamente" da bebida. Ademais 61% dos avaliadores apontaram que "certamente ou provavelmente comprariam" o produto se estivesse disponível no mercado.