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1.
Front Nutr ; 11: 1408033, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39171103

RESUMO

Objective: To evaluate the association between different types of human milk feeds and bronchopulmonary dysplasia (BPD) in preterm infants. Methods: Data on dispensed mother's own milk (MOM) and donor human milk (DHM) from Leipzig Milk Bank for hospitalized infants with a gestational age (GA) ≤32 weeks observed from birth to 36 weeks' postmenstrual age or prior discharge were used. BPD was assessed based on documented International Statistical Classification of Diseases and Related Health Problems (ICD) diagnosis and on electronic hospital records (EHR) of data on ventilation and oxygen supplementation. Associations of dispensed milk feed variations with BPD were investigated using logistic regressions in crude and adjusted models. Results: 866 infants were included with a BPD prevalence of 15.4% (EHR) and 23.2% (ICD). The mean GA was 29.1 weeks. The majority (84.4%, n = 746) of infants were nurtured with a mix of MOM, DHM supplemented by formula or parenteral (other) nutrition during hospitalization. For which, MOM comprised the highest median [Q1-Q3] percentage proportion (53[31-81] %) of this mix. Exclusive fresh milk and exclusive MOM feeds were dispensed on a mean of 40 and 34% patient-days, respectively. Statistically significant associations with lower BPD incidence were only observed for 70-80% MOM vs. DHM, and 60% fresh vs. frozen milk, in crude and adjusted models. Conclusion: Our findings suggest a protective association of MOM and fresh milk with lower odds of BPD, which may be dependent on the proportion of MOM or fresh milk administered. These results highlight the importance of MOM as an ideal source of nutrition during early infancy.

2.
Food Res Int ; 192: 114756, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39147486

RESUMO

The potential health risk of consuming dairy products made from milk processed in an artisanal manner was investigated due to possible contamination with Ptaquiloside (PTA), a carcinogenic compound found in the food chain of the bracken fern. The study aimed to assess the occurrence and stability of PTA across various processing stages, including pasteurization, cheese production, and yogurt production. Results indicated that pasteurization effectively converted all PTA to Pterosin (PTB), with PTB levels decreasing during refrigerated storage for up to two weeks. The stability and occurrence of initial PTA contamination remained unchanged in yogurt production. Biotoxin concentrations in soft cheeses decreased over time, independent of ionic strength; cheeses with low salt concentrations showed lower retention of the biotoxin within the cheese protein network. These findings offer valuable insights into the stability and occurrence of PTA, facilitating the monitoring and identification of potential adverse health effects.


Assuntos
Contaminação de Alimentos , Leite , Pteridium , Animais , Leite/química , Pteridium/química , Contaminação de Alimentos/análise , Bovinos , Sesquiterpenos/análise , Laticínios/análise , Pasteurização , Indanos/análise , Queijo/análise , Manipulação de Alimentos/métodos
3.
Food Chem X ; 23: 101633, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39108623

RESUMO

Pasteurization, as a meaningful part of food processing, has received growing attention for regulating Pickering emulsion stability. In this research, the role of pasteurization and konjac glucomannan (KGM) in the modulation of Pickering emulsion properties was investigated. The results showed that the network structure formed by KGM inhibited the agglomeration of droplets due to pasteurization, which improved the heat stability of the Pickering emulsion. Increasing the concentration of KGM improved the densification of its network structure, as evidenced by the enhanced viscoelasticity of the emulsion after pasteurization. The retention rate of ß-carotene encapsulated in the Pickering emulsion could reach 99% after pasteurization at 65 °C for 30 min. Moreover, pasteurization further enhanced the inhibitory effect of KGM on free fatty acid release and implemented a manageable release of ß-carotene. This research offers theoretical guidance for the construction of highly stable Pickering emulsions for delivering temperature-sensitive hydrophobic ingredients.

4.
Heliyon ; 10(15): e35611, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39170275

RESUMO

The quality profile, extraction yield, and fermentation chemistry of palm sap depend on various factors such as extraction technique, weather conditions, and preservation methods. This review aims to provide a detailed overview of palm sap extraction techniques and the methods for its preservation. The compositional analysis of palm sap, including physical and chemical parameters such as sugar content, acidity, and mineral composition, is discussed thoroughly. The role of microorganisms in fermentation and the effects of various influencing factors are also critically examined. Additionally, this review evaluates different preservation methods, including thermal processes, refrigeration, and electrical techniques, highlighting their effectiveness in extending the shelf life of palm sap. The review further explores the emerging impact of nanotechnology on palm sap preservation, offering insights into the latest industry challenges, developments, and future prospects. By presenting these findings, this review aims to enhance the scientific understanding of palm sap and stimulate additional research and innovation in the field, paving the way for improved production practices and product quality.

5.
Compr Rev Food Sci Food Saf ; 23(5): e13425, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39136978

RESUMO

Thermal processing is commonly employed to ensure the quality and extend the shelf-life of fruits and vegetables. Radio frequency (RF) heating has been used as a promising alternative treatment to replace conventional thermal processing methods with advantages of rapid, volumetric, and deep penetration heating characteristics. This article provides comprehensive information regarding RF heating uniformity and applications in processing of fruit and vegetable products, including disinfestation, blanching, drying, and pasteurization. The dielectric properties of fruits and vegetables and their products have also been summarized. In addition, recommendations for future research on RF heating are proposed to enhance practical applications for fruits and vegetables processing in future.


Assuntos
Manipulação de Alimentos , Frutas , Ondas de Rádio , Verduras , Frutas/química , Verduras/química , Manipulação de Alimentos/métodos , Pasteurização/métodos , Temperatura Alta
6.
Int J Biol Macromol ; 276(Pt 1): 133833, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39013513

RESUMO

Pasteurization is an effective sterilization technique for the treatment of liquid egg white (LEW), but the pasteurization temperature is generally limited because increased temperature can lead to aggregation of the proteins and affect their processing properties. In this study, phosphorylation modification was used to increase the thermal stability and pasteurization temperature of LEW, aiming to enhance the pasteurization sterilizing effect. The FT-IR results showed that the phosphate groups were successfully grafted into protein molecules, improving the order degree of protein molecules. In this case, the pasteurization temperature of LEW increased from 58 °C to 61 °C, without accompanying thermal aggregation. The molecular structural results suggested that the enhanced thermal stability was attributed to the decreased average particle size and the increased electrostatic repulsion between protein molecules, which largely reduced the turbidity of LEW during pasteurization treatment. Meanwhile, this process was dominated by noncovalent interactions (hydrophobic interactions and hydrogen bonding). Furthermore, the phosphorylation modification can synchronously improve emulsifying and foaming properties of LEW. Therefore, this work suggested that phosphorylation has great potential to improve thermal stability and pasteurization temperature of LEW, which can be utilized to extend its sterilizing effect and shelf life.


Assuntos
Clara de Ovo , Pasteurização , Temperatura , Fosforilação , Clara de Ovo/química , Tamanho da Partícula , Animais , Interações Hidrofóbicas e Hidrofílicas
7.
Food Sci Nutr ; 12(7): 4637-4655, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39055229

RESUMO

Juices from potato varieties with colored flesh contain a large amount of biologically active compounds, but they tend to darken enzymatically, which deteriorates the quality. One of the factors that can improve the color of juices is pasteurization. The aim of the study was to investigate the effect of pasteurization temperature on the anthocyanin content and color of juices from potatoes with colored flesh. The research material included juices from potato varieties with red and purple flesh. Juices pasteurized at 75 °C were characterized by the lightest color and an increase in the a* (red color) and b* (yellow color) parameters compared to unpasteurized juices. Pasteurization of juices reduced the amount of glycoalkaloids by an average of 54% compared to unpasteurized juices (larger losses in the content of α-chaconine than α-solanine). Purple potato juices showed a higher content of total polyphenols by an average of 30% and anthocyanins by 70% than juices from red potatoes. Pelargonidin and its derivatives were identified in red potato juices, while petunidin and peonidin were the most abundant in purple potato juices. Higher losses of total polyphenols were found in juices from red varieties of potatoes, while anthocyanins were less thermostable in juices from varieties with purple flesh.

8.
J Food Sci ; 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39042475

RESUMO

Orange juice is a highly nutritious beverage. Traditional pasteurization methods cause nutrient loss and taste changes. Plasma treatment (PT) is an emerging method with a high sterilization rate. This study investigated the effects of corona discharge plasma on the sterilization of orange juice by changes in color difference, total phenol content, and pH value. Single-factor experiments revealed that higher voltage (40 kV) and longer sterilization time (25 min) had better sterilization effects. Response surface analysis indicated that frequency had the greatest impact on sterilization rates, and the optimal sterilization conditions were a voltage of 44.75 kV, a frequency of 9.46 kHz, and a sterilization time of 25 min. Under these conditions, the sterilization rate reached 97.9%, meeting the national standard of 104 colony-forming units/mL (GB7101-2022). Compared to untreated juices, the color difference value was 16.32, the pH value decreased by 0.12, and the total phenol content increased by 0.669 mg/mL. However, the evaporation of water plays an important role in increasing the total phenol co. Moreover, the comparative analysis showed that PT was comparable to pasteurization in terms of sterilization effects, flavor preservation, and the concentration of bioactive components. This study provides a theoretical basis for industrial applications of PT.

9.
Adv Nutr ; 15(6): 100229, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38908896

RESUMO

BACKGROUND: Donor human milk (DHM) is an essential source of nutrition among high-risk infants (e.g., premature and low-birth weight). Holder pasteurization, a common step in DHM processing, is known to partially alter the composition of DHM; however, the impact on fat composition is historically inconsistent. OBJECTIVES: This scoping review aimed to broadly review the literature on the impact of Holder pasteurization on the fat content in DHM, with a focus on preanalytical sample mixing. METHODS: A systematic search of original, peer-reviewed research articles was conducted on 11 July, 2022. Articles were included if they compared matched raw (control) and Holder-pasteurized human milk samples and measured total lipids, cholesterol, and individual classes of fatty acids. Article review and selection was conducted by 2 independent reviewers. RESULTS: The search yielded 26 original, peer-reviewed research articles published between 1978 and 2022. Overall methodology varied considerably between studies. When study methods described any mixing for collecting raw milk, 1 (17%) of the 6 of studies reported a small change in total fat concentration following pasteurization (<5%). Alternatively, among studies that did not describe methods for mixing raw milk to ensure a representative sample, 10 (56%) of the 18 reported a significant change (≥± 5%) in total fat concentration, with changes ranging from -28.6% to +19.4%. CONCLUSIONS: This review suggests that inconsistent findings regarding the impact of Holder pasteurization on fat may be related to study methodologies, particularly preanalytical sample mixing. More research considering the role of preanalytical handling procedures and methodologies is necessary to help clarify the impact of Holder pasteurization on human milk composition.


Assuntos
Bancos de Leite Humano , Leite Humano , Pasteurização , Leite Humano/química , Humanos , Pasteurização/métodos , Lipídeos/análise , Gorduras/análise , Ácidos Graxos/análise , Feminino , Manipulação de Alimentos/métodos , Colesterol/análise
10.
Pharmaceuticals (Basel) ; 17(6)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38931428

RESUMO

Bee-collected pollen (BCP) and bee bread (BB) are honey bee products known for their beneficial biological properties. The main goal of this study was to investigate BB microbiota and its contribution to bioactivity exerted by BB. The microbiota of BB samples collected at different maturation stages was investigated via culture-independent (Next Generation Sequencing, NGS) and culture-dependent methods. Microbial communities dynamically fluctuate during BB maturation, ending in a stable microbial community structure in mature BB. Bee bread bacterial isolates were tested for phenotypes and genes implicated in the production and secretion of enzymes as well as antibacterial activity. Out of 309 bacterial isolates, 41 secreted hemicellulases, 13 cellulases, 39 amylases, 132 proteinases, 85 Coomassie brilliant blue G or R dye-degrading enzymes and 72 Malachite Green dye-degrading enzymes. Furthermore, out of 309 bacterial isolates, 42 exhibited antibacterial activity against Staphylococcus aureus, 34 against Pseudomonas aeruginosa, 47 against Salmonella enterica ser. Typhimurium and 43 against Klebsiella pneumoniae. Artificially fermented samples exerted higher antibacterial activity compared to fresh BCP, strongly indicating that BB microbiota contribute to BB antibacterial activity. Our findings suggest that BB microbiota is an underexplored source of novel antimicrobial agents and enzymes that could lead to new applications in medicine and the food industry.

11.
Heliyon ; 10(11): e32204, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38868044

RESUMO

Milk is a highly nutritious food essential for human consumption. However, traditional thermal processing methods can reduce its nutritional value and cause unwanted changes. The use of shock waves produced by pulsed electromagnetic fields (PEMFs) has been explored as a means to reduce pathogenic microorganisms. The effect of shock wave treatment on microbial load and particle distribution in packaged fresh cow's milk was investigated. Additionally, the impact of shock wave treatment on Salmonella enterica counts in a bacterial suspension of phosphate-buffered saline (PBS) was evaluated, as this bacterium is a significant milkborne pathogen. Treatment with 1000 impulses from an electromagnetic shock wave generator resulted in a 0.7-log reduction in the total bacterial count of milk. In a separate experiment, a 300-impulse shock wave treatment applied to a Salmonella enterica suspension achieved a 3-log reduction in bacterial counts. Furthermore, shock wave treatment resulted in a decrease in milk particle size compared to untreated milk. Notably, the volume of milk used in this study aligns with commercially available packaged products, enhancing the experiment's industrial relevance. The use of PEMF to generate shock waves could provide a novel approach for future studies focused on reducing the microbial load of milk and improving its homogenization.

12.
Food Chem ; 456: 139930, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-38876075

RESUMO

The effect of different sub-pasteurization heat treatments and different ripening times was investigated in this work. The metabolite profiles of 95 cheese samples were analyzed using GC-MS in order to determine the effects of thermal treatment (raw milk, 57 °C and 68 °C milk thermization) and ripening time (105 and 180 days). ANOVA test on GC-MS peaks complemented with false discovery rate correction was employed to identify the compounds whose levels significantly varied over different ripening times and thermal treatments. The univariate t-test classifier and Partial Least Square Discriminant Analysis (PLS-DA) provided acceptable classification results, with an overall accuracy in cross-validation of 76% for the univariate model and 72% from the PLS-DA. The metabolites that mostly changed with ripening time were amino acids and one endocannabinoid (i.e., arachidonoyl amide), while compounds belonging to the classes of biogenic amines and saccharides resulted in being strongly affected by the thermization process.


Assuntos
Queijo , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Metabolômica , Queijo/análise , Animais , Análise Discriminante , Leite/química , Leite/metabolismo , Manipulação de Alimentos , Aminoácidos/análise , Aminoácidos/metabolismo , Aminoácidos/química , Bovinos
13.
Food Res Int ; 190: 114546, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945559

RESUMO

The thermal treatment carried out in the processing of apple products is very likely to induce Maillard reaction to produce furfurals, which have raised toxicological concerns. This study aimed to elucidate the formation of furfural compounds in apple products treated with pasteurization and high pressure processing (HPP). The method for simultaneous determination of five furfural compounds including 5-hydroxymethyl-2-furfural (5-HMF), furfural (F), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), 2-acetylfuran (FMC), and 5-Methyl-2-furfural (MF) using high performance liquid chromatography equipped with diode array detector (HPLC-DAD) was successfully developed and validated. All five furfurals exhibited an increasing trend after the pasteurization treatment of apple clear juice, cloudy juice, and puree. 5-HMF, F, FMC, and MF were increased significantly during the precooking of apple puree. Whereas there was no significant change in the furfurals formation after apple products treated with high pressure processing (HPP) with 300 MPa and 15 min. Based on the variation of the fructose, glucose and sucrose detected in apple products after thermal treatment, it revealed that the saccharides and thermal treatment have great effect on the furfural compounds formation. The commercial fruit juice samples with different treatments and fruit puree samples treated with pasteurization were also analyzed. Five furfurals were detected more frequently in the fruit juice samples treated with pasteurization or ultra-high temperature instantaneous sterilization (UHT) than those treated with HPP. 5-HMF and FMC were detected in all fruit puree samples treated with pasteurization, followed by F, MF, and HDMF with the detection rate of 79.31 %, 72.41 %, and 51.72 %. The results could provide a reference for risk assessment of furfural compounds and dietary guidance of fruit products for human, especially for infants and young children. Moreover, moderate HPP treatment with 300 MPa and 15 min would be a worthwhile alternative processing technology in the fruit juice and puree production to reduce the formation of furfural compounds.


Assuntos
Manipulação de Alimentos , Sucos de Frutas e Vegetais , Furaldeído , Malus , Pasteurização , Pressão , Malus/química , Furaldeído/análise , Furaldeído/análogos & derivados , Cromatografia Líquida de Alta Pressão , Sucos de Frutas e Vegetais/análise , Manipulação de Alimentos/métodos , Reação de Maillard , Frutas/química , Furanos/análise
14.
Emerg Microbes Infect ; 13(1): 2364732, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38832658

RESUMO

Recently, an outbreak of highly pathogenic avian influenza A (H5N1), which carries the clade 2.3.4.4b hemagglutinin (HA) gene and has been prevalent among North American bird populations since the winter of 2021, was reported in dairy cows in the United States. As of 24 May 2024, the virus has affected 63 dairy herds across nine states and has resulted in two human infections. The virus causes unusual symptoms in dairy cows, including an unexpected drop in milk production, and thick colostrum-like milk. Notably, The US Food and Drug Administration reported that around 20% of tested retail milk samples contained H5N1 viruses, with a higher percentage of positive results from regions with infected cattle herds. Data are scant regarding how effectively pasteurization inactivates the H5N1 virus in milk. Therefore, in this study, we evaluated the thermal stability of the H5 clade 2.3.4.4b viruses, along with one human H3N2 virus and other influenza subtype viruses, including H1, H3, H7, H9, and H10 subtype viruses. We also assessed the effectiveness of pasteurization in inactivating these viruses. We found that the avian H3 virus exhibits the highest thermal stability, whereas the H5N1 viruses that belong to clade 2.3.4.4b display moderate thermal stability. Importantly, our data provide direct evidence that the standard pasteurization methods used by dairy companies are effective in inactivating all tested subtypes of influenza viruses in raw milk. Our findings indicate that thermally pasteurized milk products do not pose a safety risk to consumers.


Assuntos
Leite , Pasteurização , Animais , Pasteurização/métodos , Leite/virologia , Bovinos , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Humanos , Influenza Aviária/virologia , Influenza Aviária/transmissão , Influenza Aviária/prevenção & controle , Influenza Aviária/epidemiologia , Inativação de Vírus , Estados Unidos , Influenza Humana/virologia , Influenza Humana/transmissão , Influenza Humana/prevenção & controle , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Feminino
15.
PeerJ ; 12: e17197, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38708341

RESUMO

Waterborne transmission of the bacterium Legionella pneumophila has emerged as a major cause of severe nosocomial infections of major public health impact. The major route of transmission involves the uptake of aerosolized bacteria, often from the contaminated hot water systems of large buildings. Public health regulations aimed at controlling the mesophilic pathogen are generally concerned with acute pasteurization and maintaining high temperatures at the heating systems and throughout the plumbing of hot water systems, but L. pneumophila is often able to survive these treatments due to both bacterium-intrinsic and environmental factors. Previous work has established an experimental evolution system to model the observations of increased heat resistance in repeatedly but unsuccessfully pasteurized L. pneumophila populations. Here, we show rapid fixation of novel alleles in lineages selected for resistance to heat shock and shifts in mutational profile related to increases in the temperature of selection. Gene-level and nucleotide-level parallelisms between independently-evolving lineages show the centrality of the DnaJ/DnaK chaperone system in the heat resistance of L. pneumophila. Inference of epistatic interactions through reverse genetics shows an unexpected interaction between DnaJ/DnaK and the polyhydroxybutyrate-accumulation energy storage mechanism used by the species to survive long-term starvation in low-nutrient environments.


Assuntos
Resposta ao Choque Térmico , Legionella pneumophila , Legionella pneumophila/genética , Resposta ao Choque Térmico/genética , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Temperatura Alta , Evolução Molecular
16.
FEMS Microbiol Lett ; 3712024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38806245

RESUMO

Streptococcus pyogenes is a significant human pathogen, producing a range of virulence factors, including streptococcal pyrogenic exotoxin B (SpeB) that is associated with foodborne outbreaks. It was only known that this cysteine protease mediates cleavage of transmembrane proteins to permit bacterial penetration and is found in 25% of clinical isolates from streptococcal toxic shock syndrome patients with extreme inflammation. Its interaction with host and streptococcal proteins has been well characterized, but doubt remains about whether it constitutes a superantigen. In this study, for the first time it is shown that SpeB acts as a superantigen, similarly to other known superantigens such as staphylococcal enterotoxin A or streptococcal pyrogenic exotoxin type C, by inducing proliferation of murine splenocytes and cytokine secretion, primarily of interleukin-2 (IL-2), as shown by cytometric bead array analysis. IL-2 secretion was confirmed by enzyme-linked immunosorbent assay (ELISA) as well as secretion of interferon-γ. ELISA showed a dose-dependent relationship between SpeB concentration in splenocyte cells and IL-2 secretion levels, and it was shown that SpeB retains activity in milk pasteurized for 30 min at 63°C.


Assuntos
Proteínas de Bactérias , Proliferação de Células , Exotoxinas , Interferon gama , Interleucina-2 , Baço , Streptococcus pyogenes , Superantígenos , Animais , Interleucina-2/metabolismo , Superantígenos/imunologia , Superantígenos/metabolismo , Exotoxinas/metabolismo , Exotoxinas/imunologia , Interferon gama/metabolismo , Interferon gama/imunologia , Camundongos , Baço/microbiologia , Baço/citologia , Baço/imunologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Streptococcus pyogenes/imunologia , Streptococcus pyogenes/metabolismo , Feminino , Camundongos Endogâmicos BALB C
17.
Heliyon ; 10(10): e30905, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38803896

RESUMO

Thermal and non-thermal pasteurization (TNP) process of food is not new to food technology, disparities in the merits and demerits of the two pasteurizations necessitate their uses concurrently. Bibliometric analysis of the subject matter is expedient to analyses of database for published publications. Especially to provide times, state-of-the art innovations and prospects of the techniques. In addressing these lacunas, we utilized VOSview visualization to establish connections among crucial elements within a dataset of 495 research publications gathered from Web of Science. This approach facilitated the identification of links and collaboration networks among key factors in the research landscape. Analysis of publications indicate thermal pasteurization is an age long practices, while non-thermal pasteurization is gaining more acceptance. This study exposed ranking differences in scholar's collaboration, citations of scholars, impactful institution and most published countries. United State, China, United Kingdom have largest publications of research in TNP among the top 10 countries. Coupling network and Sankey illustration showed new area of research where new researchers and scholars can begin new phase of findings.

18.
J Agric Food Chem ; 72(19): 11062-11071, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38700435

RESUMO

Gouda cheese was produced from pasteurized milk and ripened for 30 weeks (PM-G). By application of gas chromatography/olfactometry and an aroma extract dilution analysis on the volatiles isolated by extraction/SAFE distillation, 25 odor-active compounds in the flavor dilution (FD) factor range from 16 to 4096 were identified. Butanoic acid, 2- and 3-methylbutanoic acid, and acetic acid showed the highest FD factors, and 2-phenylethanol, δ-decalactone, and δ-dodecalactone were most odor-active in the neutral-basic fraction. Quantitations by stable isotope dilution assays followed by a calculation of odor activity values (OAVs) revealed acetic acid, 3-methylbutanoic acid, butanoic acid, and butane-2,3-dione with the highest OAVs. Finally, an aroma recombinate prepared based on the quantitative data well agreed with the aroma profile of the PM-G. In Gouda cheese produced from raw (nonpasteurized) milk (RM-G), qualitatively the same set of odor-active compounds was identified. However, higher OAVs of butanoic acid, hexanoic acid, and their corresponding ethyl esters were found. On the other hand, in the PM-G, higher OAVs for 3-methylbutanoic acid, 3-methylbutanol, 3-methylbutanal, and butane-2,3-dione were determined. The different rankings of these key aroma compounds clearly reflect the aroma differences of the two Gouda-type cheeses. A higher activity of lipase in the RM-G and higher amounts of free l-leucine in PM-G on the other side were responsible for the differences in the concentrations of some key aroma compounds.


Assuntos
Queijo , Leite , Odorantes , Olfatometria , Pasteurização , Compostos Orgânicos Voláteis , Queijo/análise , Leite/química , Odorantes/análise , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/análise , Animais , Aromatizantes/química , Bovinos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Paladar
19.
Food Chem X ; 22: 101492, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38817982

RESUMO

Introducing Holstein cows on Qinghai-Tibetan Plateau is a potential solution to enhance local milk production. However, the relationship between milk quality and altitude in China remains unknown. Therefore, the components and plasmin (PL) system of raw milk from different altitudes (sea level, 1600, 2700, and 3800 m) were investigated. The daily milk production of Holstein cows and PL activity decreased as the altitude increased. However, the components content of raw milk, plasminogen (PLG)/PL ratio, activities of PLG and plasmin activator (PA) increased with altitude. The pasteurization resulted a significant decrease in PA activity of all milk and a significant increase in PL activity in milk collected at higher altitudes (2700 and 3800 m), suggesting the pasteurization was unsuitable for preserving milk at higher altitudes. This study offered references for the production and storage of milk after introducing Holstein cows on Qinghai-Tibetan Plateau.

20.
Molecules ; 29(10)2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38792230

RESUMO

Even when fresh, non-alcoholic, and low-alcoholic beers (NABLABs) exhibit significant staling defects due to premature oxidation. In this study, the antioxidant power of eleven fresh commercial NABLABs was assessed by means of three different assays: the oxygen radical absorbance capacity (ORAC), the linoleic acid-induced oxidation (TINH), and the indicator time test (ITT). Only the first two assays, both involving radicalar degradations initiated by AAPH, were found to correlate with each other. NABLABs displayed lower ORAC values than conventional beers (on average, 6127 µmol eq. Trolox/L), except for three samples made with special-colored malts or dry-hopped. Dealcoholization was the step with the greatest impact on the ORAC value (up to a 95% loss) and on flavan-3-ols, sotolon, and polyfunctional thiols, while pasteurization strongly affected color, TBA, and Strecker aldehydes. ORAC assays applied to hop, alternative cereals, and various botanical ingredients indicated that mashing with red sorghum, dry hopping/spicing, and wood maturation could bring the antioxidant power of a NABLAB close to those of conventional beers. With an ORAC value not reached by any other tested botanical ingredient (5234 µmol eq. Trolox/g), African Vernonia amygdalina leaves (traditionally used for Rwandan Ikigage beers) emerged here as the best candidate.


Assuntos
Antioxidantes , Cerveja , Oxirredução , Pasteurização , Antioxidantes/química , Cerveja/análise , Capacidade de Absorbância de Radicais de Oxigênio
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