Co-culturing Propionibacterium freudenreichii and Bifidobacterium animalis subsp. lactis improves short-chain fatty acids and vitamin B12 contents in soy whey.

The lack of vitamin B12 in unprocessed plant-based foods can lead to health problems in strict vegetarians and vegans. The main aim of this study was to investigate the potential synergy of co-culturing Bifidobacterium animalis subsp. lactis and Propionibacterium freudenreichii in improving production of vitamin B12 and short-chain fatty acids in soy whey. Different strategies including mono-, sequential and simultaneous cultures were adopted. Growth, short-chain fatty acids and vitamin B12 were assessed throughout the fermentation while free amino acids, volatiles, and isoflavones were determined on the final day. P. freudenreichii monoculture grew well in soy whey, whereas B. lactis monoculture entered the death phase by day 4. Principal component analysis demonstrates that metabolic changes in both sequential cultures did not show drastic differences to those of P. freudenreichii monoculture. However, simultaneous culturing significantly improved vitamin B12, acetic acid and propionic acid contents (1.3 times, 5 times, 2.5 times, compared to the next highest treatment [sequential cultures]) in fermented soy whey relative to other culturing modes. Hence, co-culturing of P. freudenreichii and B. lactis would provide an alternative method to improve vitamin B12, acetic acid and propionic acid contents in fermented foods.

Properties of low-fat Cheddar cheese prepared from bovine-camel milk blends: Chemical composition, microstructure, rheology, and volatile compounds.

Making cheese from camel milk (CM) presents various challenges due to its different physicochemical properties compared with bovine milk (BM). In this study, we investigated the chemical composition, proteolysis, meltability, oiling off, texture profile, color, microstructure, and rheological properties of low-fat Cheddar cheese (LFCC) prepared from BM-CM blends. LFCC was produced from BM or BM supplemented with 15% CM (CM15) and 30% CM (CM30), and analyzed after 14, 60, 120, and 180 d of ripening at 8°C. Except for salt content, no significant differences were observed among LFCC from BM, CM15, and CM30. The addition of CM increased the meltability and oiling off in the resulting cheese throughout storage. With respect to color properties, after melting, LFCC CM30 showed lower L* values than LFCC made from BM and CM15, and a* and b* values were higher than those of BM and CM15 samples. LFCC from CM30 also exhibited lower hardness compared with the other cheeses. Moreover, LFCC made from BM showed a rough granular surface, but cheese samples made from BM-CM blends exhibited a smooth surface. The rheological parameters, including storage modulus, loss modulus, and loss tangent, varied among cheese treatments. The determined acetoin and short-chain volatile acids (C2-C6) in LFCC were affected by the use of CM, because CM15 showed significantly higher amounts than BM and CM30, respectively. The detailed interactions between BM and CM in the cheese matrix should be further investigated.

Invited review: Camel milk and gut health-Understanding digestibility and the effect on gut microbiota.

Camel milk (CM), known for its immune-regulatory, anti-inflammatory, antiapoptotic, and antidiabetic properties, is a natural healthy food. It is easily digestible due to the high levels of ß-casein and diverse secreted antibodies, exhibiting superior antibacterial and antiviral activities compared with bovine milk. ß-casein is less allergic and more digestible because it is more susceptible to digestive hydrolysis in the gut; therefore, higher levels of ß-casein make CM advantageous for human health. Furthermore, antibodies help the digestive system by destroying the antigens, which are then overwhelmed and digested by macrophages. The connection between the gut microbiota and human health has gained substantial research attention, as it offers potential benefits and supports disease treatment. The gut microbiota has a vital role in regulating the host's health because it helps in several biological functions, such as protection against pathogens, immune function regulation, energy harvesting from digested foods, and reinforcement of digestive tract biochemical barriers. These functions could be affected by the changes in the gut microbiota profile, and gut microbiota differences are associated with several diseases, such as inflammatory bowel disease, colon cancer, irritable bowel disorder, mental illness, allergy, and obesity. This review focuses on the digestibility of CM components, particularly protein and fat, and their influence on gut microbiota modulation. Notably, the hypoallergenic properties and small fat globules of CM contribute to its enhanced digestibility. Considering the rapid digestion of its proteins under conditions simulating infant gastrointestinal digestion, CM exhibits promise as a potential alternative for infant formula preparation due to the high ß-/αs-casein ratio and protective proteins, in addition to the absence of ß-lactoglobulin.

The potential of postbiotics as a novel approach in food packaging and biopreservation: a systematic review of the latest developments.

Metabolic by-products are part of the so-called postbiotics of probiotics and other beneficial microorganisms, particularly lactic acid bacteria, which have gained popularity as a feasible alternative to improving food quality and safety. Postbiotics in dry and liquid forms can be easily integrated into food formulations and packaging materials, exhibiting antimicrobial and antioxidant effects owing to the presence of multiple antimicrobials, such as organic acids, bacteriocins, exopolysaccharides and bioactive peptides. Postbiotics can thus control the growth of pathogens and spoilage microorganisms, thereby extending the shelf life of food products. Because of their ability to be easily manufactured without requiring extensive processing, postbiotics are regarded as a safer and more sustainable alternative to synthetic preservatives, which can have negative environmental consequences. Additionally, food manufacturers can readily adopt postbiotics in food formulations without significant modifications. This systematic review provides an in-depth analysis of studies on the use of postbiotics in the biopreservation and packaging of a wide range of food products. The review evaluates and discusses the types of microorganisms, postbiotics preparation and modification techniques, methods of usage in dairy products, meat, poultry, seafood, fruits, vegetables, bread, and egg, and their effects on food quality and safety.

Effects of dexmedetomidine on evoked potentials in spinal surgery under combined intravenous inhalation anesthesia: a randomized controlled trial.

OBJECTIVE: We aimed to investigate the effects of different doses of dexmedetomidine (Dex) on evoked potentials in adult patients undergoing spinal surgery under intravenous anesthesia with low-concentration desflurane. METHODS: Ninety patients were divided into three groups at random. To maintain anesthesia in the control group (group C), desflurane 0.3 MAC (minimal alveolar concentration), propofol, and remifentanil were administered. Dex (0.5 µg·kg-1) was injected for 10 min as a loading dose in the low-dose Dex group (group DL), then adjusted to 0.2 µg·kg-1·h-1 until the operation was completed. Dex (1 µg·kg-1) was injected for 10 min as a loading dose in the high-dose Dex group (group DH), then adjusted to 0.7 µg·kg-1·h-1 until the operation was completed. The additional medications were similar to those given to group C. The perioperative hemodynamics, body temperature, intraoperative drug dosages, fluid volume, urine volume, blood loss, the latency and amplitude of somatosensory evoked potentials (SEPs) at four different time points, the incidence of positive cases of SEPs and transcranial motor evoked potentials (tcMEPs), and perioperative adverse reactions were all recorded. RESULTS: Data from 79 patients were analyzed. The MAP measured at points T2-T4 in group DH was higher than at corresponding points in group C (P < 0.05). The MAP at point T4 in group DL was higher than at corresponding points in group C (P < 0.05). The remifentanil dosage in group DH was significantly lower than in group C (P = 0.015). The fluid volume in group DL was significantly lower than in group C (P = 0.009). There were no significant differences among the three groups in the amplitude and latency of SEP at different time points, nor in the incidence of warning SEP signals. The incidence of positive tcMEP signals did not differ significantly between groups C and DL (P > 0.05), but was significantly higher in group DH than in groups DL (P < 0.05) or C (P < 0.05). The incidence of intraoperative hypertension was significantly higher in group DH than in group C (P = 0.017). CONCLUSIONS: Low-dose Dex has no effect on the SEPs and tcMEPs monitoring during spinal surgery. High-dose Dex has no effect on SEPs monitoring, but it may increase the rate of false positive tcMEPs signals and the incidence of intraoperative hypertension. TRIAL REGISTRATION: This study has completed the registration of the Chinese Clinical Trial Center at 11/09/2020 with the registration number ChiCTR2000038154.

Fermented camel milk influenced by soy extract: Apparent viscosity, viscoelastic properties, thixotropic behavior, and biological activities.

During fermentation, camel milk forms a fragile, acid-induced gel, which is less stable compared with the gel formed by bovine milk. In this study, camel milk was supplemented with different levels of soy extract, and the obtained blends were fermented with 2 different starter culture strains (a high acidic culture and a low acidic culture). The camel milk-soy extract yogurt treatments were evaluated for pH value, acidity, total phenolic compounds, antioxidant capacities, degree of hydrolysis, α-amylase and α-glucosidase inhibition, angiotensin-converting enzyme inhibition, antiproliferative activities, and rheological properties after 1 and 21 d of storage at 4°C. The results revealed that some of the investigated parameters were significantly affected by the starter culture strain and storage period. For instance, the effect of starter cultures was evident for the degree of hydrolysis, antioxidant capacities, proliferation inhibition, and rheological properties because these treatments led to different responses. Furthermore, the characteristics of camel milk-soy extract yogurt were also influenced by the supplementation level of soy extract, particularly after 21 d of storage. This study could provide valuable knowledge to the dairy industry because it highlighted the characteristics of camel milk-soy yogurt prepared with 2 different starter culture strains.

Triazophos exposure on maternal Daphnia magna at environmental-related concentrations revealed toxic effects to its offspring.

Due to chemical and photochemical stability, triazophos has been frequently detected in rivers and oceans over the years with extensive use for pest control in agriculture, and it has become a worldwide ecological concern to the aquatic environment. Until now, fewer data are available regarding the potential long-term adverse effects of triazophos on aquatic invertebrates, which plays an essential role in aquatic food webs, as a key group for water ecosystems. In this experiment, the F1- and F2 progenies of Daphnia magna were recovered when daphnias (F0) exposure to triazophos at environmental-related concentrations (0.1 and 1.0 µg/L) for 21 d; and the indexes related to phenotypic traits, reproduction and gene expression were measured in tested animals. The results showed that heart rate and total number of neonates in exposed F0-daphnias were significantly lower than those of control group, and the detoxification genes (HR96 and P-gp) were up-regulated while genes related reproduction (Vtg) and molting (Nvd and Shd) were significantly down-regulated. The heart rate and individual size of F1-daphnias (<24 h) were significantly reduced in the treatment group. After 21-d recovery, the heart rate and expression of HR96, P-gp, Vtg, Nvd and Shd were declined in F1-daphnias. There was no obvious difference of morphological traits and heart rate between treatment and control in F2-daphnias (<24 h). In summary, daphnias (F0) exposure to triazophos with environmental dose could raise toxic effects on its offspring (F1), which is mainly manifested by reduced heart rate, the accumulated number and individual size of offspring and decreased expression of genes related to molting and reproduction.

Detection of Salmonella Enteritidis in Milk Using Conductometric Immunosensor Coated on Polyaniline/Zinc Oxide Nanocomposite.

The demand for rapid and accurate detection methods for Salmonella Enteritidis necessitates the development of highly sensitive and specific biosensors to ensure proper monitoring of food safety and quality requirements in the food sector and to secure human health. This study focused on development of a polyaniline/zinc oxide (PANI/ZnO) nanocomposite film on a gold electrode conductometric immunosensor for detection of Salmonella Enteritidis. The sensor was modified with monoclonal anti-Salmonella Enteritidis antibodies as biorecognition elements. The fabricated sensor was able to detect and quantify the target pathogen within 30 min and showed a good detection range from 101 to 105 colony-forming units (CFU)/mL for Salmonella Enteritidis and a minimum detection limit of 6.44 CFU/mL in 0.1% peptone water. Additionally, the fabricated sensor showed good selectivity and detection limit toward the target bacterium and successfully determined Salmonella Enteritidis content in ultrahigh heat-treated skim milk samples without pretreatment of the food sample.

Enzymatic treatment, unfermented and fermented fruit-based products: current state of knowledge.

In recent years, food manufacturers are increasingly utilizing enzymes in the production of fruit-based (unfermented and fermented) products to increase yield and maximize product quality in a cost-effective manner. Depending on the fruits and desired product characteristics, different enzymes (e.g. pectinase, cellulase, hemicellulase, amylase, and protease) are used alone or in combinations to achieve optimized processing conditions and improve nutritional and sensorial quality. In this review, the mechanisms of action and sources of different enzymes, as well as their effects on the physicochemical, nutritional, and organoleptic properties of unfermented and fermented fruit-based products are summarized and discussed, respectively. In general, the application of enzymatic hydrolysis treatment (EHT) in unfermented fruit-based product helps to achieve four main purposes: (i) viscosity reduction (easy to filter), (ii) clarification (improved appearance/clarity), (iii) better nutritional quality (increase in polyphenolics) and (iv) enhanced organoleptic characteristic (brighter color and complex aroma profile). In addition, EHT provides numerous other advantages to fermented fruit-based products such as better fermentation efficiency and enrichment in aroma. To meet the demand for new market trends, researchers and manufacturers are increasingly employing non-Saccharomyces yeast (with enzymatic activities) alone or in tandem with Saccharomyces cerevisiae to produce complex flavor profile in fermented fruit-based products. Therefore, this review also evaluates the potential of some non-Saccharomyces yeasts with enzymatic activities and how their utilization helps to tailor wines with unique aroma profile. Lastly, in view of an increase in lactose-intolerant individuals, the potential of fermented probiotic fruit juice as an alternative to dairy-based probiotic products is discussed.

Effect of thermal treatment on aroma compound formation in yeast fermented pork hydrolysate supplemented with xylose and cysteine.

BACKGROUND: The present study has revealed an innovative method of coupling enzyme hydrolysis, yeast fermentation and thermal treatment to transform pork trimmings into a seasoning product. The pork trimmings were first enzymatically hydrolysed and fermented into liquid pork hydrolysates, followed by adding xylose and cysteine, then heat treatment. RESULTS: Approximately 28% of xylose and 7% of glucose were consumed, and amino acids increased by around 31% after thermal treatment. The heated yeast fermented pork hydrolysates possessed a characteristic 'savoury, roasted-meat and fruity sweet' aroma as a result of the formation of thermally induced sulfur-containing volatiles such as 2-furfurylthiol, as well as retention of yeast generated esters including isoamyl acetate and hexyl acetate. CONCLUSION: The heat-treated fermented pork hydrolysates impart an attractive and innovative aroma because of yeast fermentation and heat treatment. The innovative heated fermented pork hydrolysates could be further processed into a nutritional and savoury pork broth and/or a meat sauce. © 2021 Society of Chemical Industry.

Invited review: Characterization of new probiotics from dairy and nondairy products-Insights into acid tolerance, bile metabolism and tolerance, and adhesion capability.

The selection of potential probiotic strains that possess the physiological capacity of performing successfully in the gastrointestinal tract (GIT) is a critical challenge. Probiotic microorganisms must tolerate the deleterious effects of various stresses to survive passage and function in the human GIT. Adhesion to the intestinal mucosa is also an important aspect. Recently, numerous studies have been performed concerning the selection and evaluation of novel probiotic microorganisms, mainly probiotic bacteria isolated from dairy and nondairy products. Therefore, it would be crucial to critically review the assessment methods employed to select the potential probiotics. This article aims to review and discuss the recent approaches, methods used for the selection, and outcomes of the evaluation of novel probiotic strains with the main purpose of supporting future probiotic microbial assessment studies. The findings and approaches used for assessing acid tolerance, bile metabolism and tolerance, and adhesion capability are the focus of this review. In addition, probiotic bile deconjugation and bile salt hydrolysis are explored. The selection of a new probiotic strain has mainly been based on the in vitro tolerance of physiologically related stresses including low pH and bile, to ensure that the potential probiotic microorganism can survive the harsh conditions of the GIT. However, the varied experimental conditions used in these studies (different types of media, bile, pH, and incubation time) hamper the comparison of the results of these investigations. Therefore, standardization of experimental conditions for characterizing and selecting probiotics is warranted.

Biotransformation of pork trimmings into protein hydrolysate using microbial proteases aided by response surface methodology.

Meat processing generates significant amounts of by-products such as trimmings that require further valorization. In this study, pork trimmings were transformed with proteases to protein hydrolysates that may find applications as nutritional and/or flavouring ingredients. Four microbial proteases-Flavourzyme, Protamex, Alcalase, and Neutrase were explored to hydrolyze pork trimmings. Flavourzyme, which showed the highest degree of hydrolysis (DH), was selected to optimize the key hydrolytic parameters using response surface methodology (RSM) with Box-Behnken design. The optimal conditions were found to be 6: 100 (enzyme/substrate ratio), 50 °C, and pH 6 for a maximum DH at 48% after 6 h of hydrolysis. The protein hydrolysate was high in free amino acids (17 g/100 g dry weight), of which essential and taste-active amino acids accounted for 42% and 20%, respectively. The obtained hydrolysate may be considered suitable as a nutritional and/or flavouring ingredient.

Work-family balance and the subjective well-being of rural women in Sichuan, China.

BACKGROUND: Due to the great burden of family and the conflicts among family, society and career roles resulting from migrant working, rural women suffer more conflicts between work and family and need more social attention. Previous studies of the conflicts between family and work mainly focus on the group of career women, and there is a lack of the research on the conflicts between work and family of rural women, which needs to be systematically and further studied. METHODS: This study used a sample survey of 380 rural women in rural areas of Sichuan Province to measure rural women's cognition of work-family, coordination and handling of conflicts, post-conflict choices, and subjective well-being; the study constructs an ordered multi-class logistic regression model to explore the impact of work-family conflict on the subjective well-being of rural women in rural regions. RESULTS: The study result shows that: (1) The level of subjective well-being of rural women is generally high, and 70% of women feel satisfied or very satisfied. (2) The factor which impacts the subjective well-being among rural women most is work-interfering-with-family conflict, followed by work-family balance and confidence in conflict coordination. CONCLUSION: This study can enhance our understanding of rural women in rural areas, and provide a reference for formulating policies to improve people's life satisfaction.

Survival of probiotic strain Lactobacillus paracasei L26 during co-fermentation with S. cerevisiae for the development of a novel beer beverage.

Amidst the rising popularity of craft beers, it would be opportune to develop a novel, unfiltered and unpasteurized sour beer with high probiotic live counts. However, as beer typically contains hop iso-α-acids that prevent the growth and survival of probiotic lactic acid bacteria, the use of suitable fermentation strategies is crucial. The growth, and survival of the probiotic bacterium, Lactobacillus paracasei L26, were assessed during a 10-day co-fermentation period with a brewer's yeast, Saccharomyces cerevisiae S-04, in unhopped wort. Isomerized hop extract was added prior to storage of the beers at 25 °C and 5 °C. During co-fermentation in unhopped wort, L. paracasei L26 maintained high viable cell counts above 8 Log CFU/mL, indicating species compatibility with the yeast. The majority of fermentable sugars were attenuated by S. cerevisiae S-04, with a concomitant production of alcohols and esters. Significant amounts of lactic acid were produced by L. paracasei L26 (P < 0.05). During storage with added isomerized hop extract, maximal probiotic viability enhancing effects were observed in the presence of live S. cerevisiae S-04, in combination with refrigeration. The results suggest that beers could be a vehicle for probiotic delivery under appropriate conditions. This was the first study demonstrating the feasibility of utilizing probiotic lactobacilli as starter cultures in beer brewing.

Labor migration and farmland abandonment in rural China: Empirical results and policy implications.

Farmland abandonment is a universal socio-economic phenomenon in various countries in the world. However, there is a lack of the large-sample empirical research on rural households' farmland abandonment in China, and few studies have explored the quantitative influences of labor migration on rural households' farmland abandonment. This study uses the survey data of 8031 rural households from 27 provinces (cities) in China. It analyzes the spatial distribution characteristics of labor migration and farmland abandonment on the basis of provinces (cities). Moreover, it constructs the iv-probit models and the iv-tobit models to quantitatively explore the influences of off-farm employment and part-time employment on rural households' farmland abandonment. The results show that: Labor migration and farmland abandonment in various provinces (cities) of China present the trend of spatial area agglomeration. The regional differences of off-farm laborers are significant, whereas the regional differences of part-time laborers are relatively small; Labor migration would promote rural households' farmland abandonment. When other conditions remain unchanged, with every 10% increase in off-farm employment and part-time employment, the average probability of rural households' farmland abandonment increases by 4% and 5%, respectively, and the average farmland area that rural household abandons increases by 3% and 5%, respectively. This study can enhance the understanding of the relationship between labor migration and rural households' farmland abandonment in China, so as to provide reference for the rational allocation of labor resources and the formulation of the policies related to ensuring food security.

Bioconversion of green volatiles in okara (soybean residue) into esters by coupling enzyme catalysis and yeast (Lindnera saturnus) fermentation.

Okara (soybean residue), a by-product from soymilk and tofu production, has a green, grassy off odour as it contains a large amount of aldehydes. This work investigated the rate-limiting enzyme(s) in the formation of aldehydes in okara and the pathways leading to their bioconversion into fruity, pleasant-smelling esters by the yeast Lindnera saturnus. Lipase and hydroperoxide lyase were shown to be rate-limiting enzymes while endogenous soy lipoxygenase was also crucial for the production of aldehydes in okara. Subsequent fermentation of okara by L. saturnus increased the amount of esters by about 70 times to 165-277 µg/g dried okara. The generation of C7 esters followed our hypothesised pathway, while that for C6 esters was mainly affected by L. saturnus. This study presents a simple and inexpensive one-pot setup for the natural bio-production of esters from okara.

Evaluation of five commercial non-Saccharomyces yeasts in fermentation of soy (tofu) whey into an alcoholic beverage.

Soy (tofu) whey is a nutritious liquid substrate that is often discarded by tofu manufacturers. Recent research has shown that tofu whey can be converted into a soy alcoholic beverage using Saccharomyces yeasts. In this study, five commercially available non-Saccharomyces yeasts (Torulaspora delbrueckii; Lachancea thermotolerans; Metschnikowia pulcherrima; Pichia kluyveri and Williopsis saturnus) were evaluated in tofu whey fermentation and each of the yeasts showed different growth kinetics and fermentation performance. T. delbrueckii and L. thermotolerans consumed the supplemented sucrose and produced 6-7% (v/v) ethanol, while M. pulcherrima, P. kluyveri and W. saturnus only utilized the endogenous fructose and glucose, producing trace levels of ethanol. Besides, different yeasts showed different ß-glucosidase activities with 22-97% reduction in isoflavone glucosides; T. delbrueckii, L. thermotolerans and W. saturnus also decreased the level of GABA in tofu whey. Endogenous volatile compounds (mainly short-chain aldehydes) in tofu whey were reduced to trace levels, but different volatile compounds were produced by different yeasts at varying levels that can contribute to the different aroma profiles of the beverages. Therefore, selection of appropriate non-Saccharomyces yeasts can serve as a new strategy to valorize tofu whey and alter the aroma profile of the beverage.

The Possible Reduction Mechanism of Volatile Sulfur Compounds during Durian Wine Fermentation Verified in Modified Buffers.

Durian fruit is rich in volatile sulfur compounds (VSCs), especially thiols and disulfides, which contribute to its onion-like odor. After fermentation, these VSCs were reduced to trace or undetectable levels in durian wine. The possible reduction mechanism of these VSCs (especially diethyl disulfide and ethanethiol) was investigated in a modified buffer in the presence of sulfite at different pH. An interconversion between diethyl disulfide and ethanethiol was found to be dependent on the pH: the higher the pH, the higher production of ethanethiol. It is suggested that, during durian wine fermentation, disulfides endogenous to durian pulp might be firstly converted into their corresponding thiols in the presence of reductant sulfite formed by yeast. The produced thiols as well as the thiols endogenous to the durian pulp were then removed by the mannoproteins of yeast lees.

Biotransformation with cellulase, hemicellulase and Yarrowia lipolytica boosts health benefits of okara.

Okara (soybean residue) is a highly perishable food processing by-product from soymilk and tofu manufacture. It contains a large proportion of insoluble dietary fibre (40-60% on a dry basis), as well as digestion-resistant proteins, trypsin inhibitors and phytic acid. These factors contribute lead to the under-utilisation of okara. To improve the overall nutritional quality of okara, sequential saccharification of okara by Celluclast® 1.5L (cellulase) or Viscozyme® L (cellulase and hemicellulase) and fermentation by the yeast Yarrowia lipolytica were performed. The changes in the antioxidant capacity, amino acids, phenolic acids, isoflavones, phytic acid and dietary fibre during biotransformation were studied. Carbohydrase pre-treatment increased the amounts of monosaccharides, trans-cinnamic acid and aglycone isoflavones in okara. After fermentation, the okara had higher antioxidant activity and greater amounts of total amino acids and ferulic acid. Some positive interactions between the carbohydrase and Y. lipolytica were hypothesised: the carbohydrase and Y. lipolytica proteases could have synergised with each other to break down the okara secondary cell wall more efficiently. After 52 h, Celluclast® 1.5 L and Viscozyme® L significantly reduced the insoluble dietary fibre content from 61.9 ± 0.6 to 45.6 ± 3.0% and 24.7 ± 0.3%, respectively (all w/w, dry basis), while increasing the soluble dietary fibre content by about onefold. Both carbohydrases also increased the amounts of monosaccharides, trans-cinnamic acid, and aglycone isoflavones in okara. The addition of Y. lipolytica led to a higher antioxidant capacity and greater amounts of total amino acids and ferulic acid in okara. The overall improvements in the digestibility and potential health benefits of okara highlight the promising applicability of biotransformation in okara valorisation.

Combined effects of fermentation temperature and pH on kinetic changes of chemical constituents of durian wine fermented with Saccharomyces cerevisiae.

This study investigated the effects of temperature (20 and 30 °C) and pH (pH 3.1, 3.9) on kinetic changes of chemical constituents of the durian wine fermented with Saccharomyces cerevisiae. Temperature significantly affected growth of S. cerevisiae EC-1118 regardless of pH with a higher temperature leading to a faster cell death. The pH had a more significant effect on ethanol production than temperature with higher production at 20 °C (5.95%, v/v) and 30 °C (5.56%, v/v) at pH 3.9, relative to that at pH 3.1 (5.25 and 5.01%, v/v). However, relatively higher levels of isobutyl alcohol and isoamyl alcohol up to 64.52 ± 6.39 and 56.27 ± 3.00 mg/L, respectively, were produced at pH 3.1 than at pH 3.9 regardless of temperature. In contrast, production of esters was more affected by temperature than pH, where levels of ethyl esters (ethyl esters of octanoate, nonanoate, and decanoate) and acetate esters (ethyl acetate and isoamyl acetate) were significantly higher up to 2.13 ± 0.23 and 4.61 ± 0.22 mg/L, respectively, at 20 °C than at 30 °C. On the other hand, higher temperature improved the reduction of volatile sulfur compounds. This study illustrated that temperature control would be a more effective tool than pH in modulating the resulting aroma compound profile of durian wine.