Regulation and mechanism of enzyme metabolism in germinated hemp seeds by ultrasound combined with exogenous calcium chloride treatment.

γ-aminobutyric acid (GABA) plays an important role in anti-anxiety by inhibiting neurotransmitter in the central nervous system (CNS) of mammals, which is generated in the germinating seeds. The key enzymes activity of GABA metabolism pathway and nutrients content in hemp seeds during germination were studied after treated with ultrasound and CaCl2. The mechanism of exogenous stress on key enzymes in GABA metabolism pathway was investigated by molecular dynamics simulation. The results showed that ultrasonic combined with 1.5 mmol·L-1CaCl2 significantly increased the activities of glutamate decarboxylase (GAD) and GABA transaminase (GABA-T) in seeds, and promoted the conversion of glutamate to GABA, resulting in the decrease of glutamate content and the accumulation of GABA. Molecular dynamics simulations revealed that Ca2+ environment enhanced the activity of GAD and GABA-T enzymes by altering their secondary structure, exposing their hydrophobic residues. Ultrasound, germination and CaCl2 stress improved the nutritional value of hemp seeds.

Non-thermal techniques as an approach to modify the structure of milk proteins and improve their functionalities: a review of novel preparation.

BACKGROUND: Milk proteins (MPs) have been widely used in the food industry due to their excellent functionalities. However, MPs are thermal-unstable substances and their functional properties are easily affected by heat treatment. Emerging non-thermal approaches (i.e., high-pressure homogenization (HPH), ultrasound (US), pulsed electric field (PEF)) have been increasingly popular. A detailed understanding of these approaches' impacts on the structure and functionalities of MPs can provide theoretical guidance for further development to accelerate their industrialization. SCOPE AND APPROACH: This review assesses the mechanisms of HPH, US and PEF technologies on the structure and functionalities of MPs from molecular, mesoscopic and macroscopic levels, elucidates the modifications of MPs by these theologies combined with other methods, and further discusses their existing issues and the development in the food filed. KEY FINDINGS AND CONCLUSIONS: The structure of MPs changed after HPH, US and PEF treatment, affecting their functionalities. The changes in these properties of MPs are related to treated-parameters of used-technologies, the concentration of MPs, as well as molecular properties. Additionally, these technologies combined with other methods could obtain some outstanding functional properties for MPs. If properly managed, these theologies can be tailored for manufacturing superior functional MPs for various processing fields.

Evaluating the role of glycyrrhizic acid on the dynamic stabilization mechanism of the emulsion prepared by α-Lactalbumin: Experimental and silico approaches.

The role of glycyrrhizic acid (GA) on the dynamic stabilization mechanism of the α-Lactalbumin (α-La) emulsion was evaluated in this study. Smaller particle size and higher zeta potential value were observed in the α-La/GA emulsion as compared to the α-La emulsion. Ultra-high-resolution microscopy revealed that the interfacial film formed around oil droplets by α-La/GA complex was thicker compared to that of either α-La or GA. The appearance of a new peak at 1679 cm-1 in FTIR of the α-La/GA emulsion attributed to the stretching vibration of CO, providing evidence of the formation of a stable emulsion system. The results from dynamic molecular simulation showed GA induced the formation of an interfacial adsorption layer at the oil-water interface, reducing the migration ability of GA. The findings indicate that the presence of GA in the α-La emulsion effectively enhances its stability, highlighting its potential as a valuable emulsifying agent for various industrial applications.

Insight into comparison of binding interactions and biological activities of whey protein isolate exposed prior to two structurally different sterols.

Although sterols have multiple physiological functions, low solubility and weak emulsifying properties of sterols affect their application in the food industry. However, binding interaction between protein and sterol potentially enhances its biological activities and emulsifying properties. In this work, effects of two structurally different sterols, namely ergosterol (ES) and γ-oryzanol (γS) on binding interactions, emulsifying properties, and biological activities of whey protein isolate (WPI)-sterol complexes were investigated and compared. Fluorescence spectroscopies and molecular docking presented that binding affinity of WPI treated with γS was stronger than that with ES. Importantly, WPI-γS exhibited stronger absolute value of ζ-potential, surface hydrophobicity, emulsifying characteristics and biological activities than WPI-ES. Principal component analysis (PCA) showed that emulsifying characteristics and biological activities of all the samples were positively correlated. This study provided a theoretical basis for the development and practical application of protein-sterol complexes as functional ingredients in food industry.

Research Advances of Lactoferrin in Electrostatic Spinning, Nano Self-Assembly, and Immune and Gut Microbiota Regulation.

Lactoferrin (LF) is a naturally present iron-binding globulin with the structural properties of an N-lobe strongly positively charged terminus and a cage-like structure of nano self-assembly encapsulation. These unique structural properties give it potential for development in the fields of electrostatic spinning, targeted delivery systems, and the gut-brain axis. This review will provide an overview of LF's unique structure, encapsulation, and targeted transport capabilities, as well as its applications in immunity and gut microbiota regulation. First, the microstructure of LF is summarized and compared with its homologous ferritin, revealing both structural and functional similarities and differences between them. Second, the electrostatic interactions of LF and its application in electrostatic spinning are summarized. Its positive charge properties can be applied to functional environmental protection packaging materials and to improving drug stability and antiviral effects, while electrostatic spinning can promote bone regeneration and anti-inflammatory effects. Then the nano self-assembly behavior of LF is exploited as a cage-like protein to encapsulate bioactive substances to construct functional targeted delivery systems for applications such as contrast agents, antibacterial dressings, anti-cancer therapy, and gene delivery. In addition, some covalent and noncovalent interactions of LF in the Maillard reaction and protein interactions and other topics are briefly discussed. Finally, LF may affect immunological function via controlling the gut microbiota. In conclusion, this paper reviews the research advances of LF in electrostatic spinning, nano self-assembly, and immune and gut microbiota regulation, aiming to provide a reference for its application in the food and pharmaceutical fields.

Beverages containing Lactobacillus paracasei LC-37 improved functional dyspepsia through regulation of the intestinal microbiota and their metabolites.

Functional dyspepsia (FD) is a common disease of the digestive system and probiotics have been reported to be effective in the treatment of functional gastrointestinal diseases. The aim of this study was to determine the effect of the beverage containing Lactobacillus paracasei LC-37 (LC-37) and its ability to relieve symptoms of FD by a randomized clinical trial. Due to the mechanistic complexity underlying FD, intestinal microbiota and stool metabolomes were also evaluated. The results showed that FD was relieved in participants after treatment with the beverage containing LC-37 for 14 and 28 d. The clinical symptom scores were significantly decreased after these times (abdominal pain and belching were significantly decreased after 14 d and almost absent after 28 d of treatment). Probiotics, such as those containing the Lactobacillus, Lactococcus, and Weissella, significantly increased, and the abundance of harmful bacteria such as Lachnocliostridium significantly decreased. Furthermore, relevant beneficial intestinal metabolites such as pelargonic acid, benzoic acid, and short-chain fatty acids increased, and harmful intestinal metabolites such as hippuric acid decreased. Taken together, these findings suggested that the beverages containing LC-37 can increase the abundance of probiotics and decrease pathogenic bacteria, and thereby improve beneficial intestinal metabolites. Therefore, the beverages containing LC-37 may provide a natural alternative to combat FD.

Advancement on Milk Fat Globule Membrane: Separation, Identification, and Functional Properties.

Dairy products have become more common in people's daily diets in recent years, and numerous useful components derived from milk are widely employed in the food industry. Milk fat globule membrane (MFGM) is a kind of film that encases milk fat globules, and has been shown to have a high nutritional value. In this work, the protein, lipid, carbohydrate, and other components of MFGM are discussed, and also common separation, preparation, and analysis technologies, physicochemical properties, and functional features of MFGM are reviewed, to provide some guidance for the development and utilization of MFGM.

The Use of Trisodium Citrate to Improve the Textural Properties of Acid-Induced, Transglutaminase-Treated Micellar Casein Gels.

In this study, the effect of trisodium citrate on the textural properties and microstructure of acid-induced, transglutaminase-treated micellar casein gels was investigated. Various concentrations of trisodium citrate (0 mmol/L, 10 mmol/L, 20 mmol/L, and 30 mmol/L) were added to micellar casein dispersions. After being treated with microbial transglutaminase (mTGase), all dispersions were acidified with 1.3% (w/v) gluconodelta-lactone (GDL) to pH 4.4⁻4.6. As the concentration of trisodium citrate increased from 0 mmol/L to 30 mmol/L, the firmness and water-holding capacity increased significantly. The final storage modulus (G') of casein gels was positively related to the concentration of trisodium citrate prior to mTGase treatment of micellar casein dispersions. Cryo-scanning electron microscopy images indicated that more interconnected networks and smaller pores were present in the gels with higher concentrations of trisodium citrate. Overall, when micellar casein dispersions are treated with trisodium citrate prior to mTGase crosslinking, the resulted acid-induced gels are firmer and the syneresis is reduced.

Characterization and comparison of the structure and antioxidant activity of glycosylated whey peptides from two pathways.

Glycosylated whey peptides (WPP-Gal A and WPP-Gal B) were formed from two pathways. WPP-Gal A showed higher browning intensity and fluorescence intensity than WPP-Gal B. Loss of amino groups and reducing sugar was heavier for WPP-Gal A than WPP-Gal B. Size exclusion chromatography revealed that WPP-Gal A and B had similar curves, but the molecular weight distribution of WPP-Gal B was more extensive than that of WPP-Gal A. Particle size was larger for WPP-Gal B than WPP-Gal A. Furthermore, WPP-Gal A showed greater antioxidant activity than WPP-Gal B. FT-IR analysis indicated that vibrations of several chemical bonds in amide I, II and III bands of WPP-Gal A were more obvious than those of WPP-Gal B. WPP-Gal A showed greater Caco-2 cell proliferation than WPP-Gal B. Therefore, WPP-Gal A showed more significant structural and characteristic changes, higher antioxidant activity and better proliferative activity than WPP-Gal B.

Effects of ultrasound treatment on physico-chemical, functional properties and antioxidant activity of whey protein isolate in the presence of calcium lactate.

BACKGROUND: The aim of this study was to investigate the effects of ultrasound applied at various powers (0, 200, 400, 600 or 800 W) and for different times (20 or 40 min) on the physico-chemical, functional properties and antioxidant activities of whey protein isolate (WPI) dispersions in the presence of 1.20 mmol L-1 calcium lactate. RESULTS: Surface hydrophobicity and free sulfhydryl group of the WPI dispersions containing 1.2 mmol L-1 calcium lactate were significantly enhanced after sonication. Furthermore, particle size of WPI dispersions containing 1.20 mmol L-1 calcium lactate was minimised after sonication. Scanning electron microscopy of sonicated WPI suspensions containing 1.20 mmol L-1 calcium lactate showed that WPI microstructure had significantly changed. After WPI dispersions were treated by sonication assisted with calcium lactate, its gel strength enhanced and solubility decreased. Gel strength of sonicated WPI dispersions (600 W, 40 min) was the maximum among all the WPI treatments. Emulsification activity of sonicated WPI dispersions reduced while its emulsion stability increased. The DPPH radical scavenging activity and ferrous reducing power of sonicated WPI dispersions mostly increased. CONCLUSION: Ultrasound treatments induced structural changes in WPI molecules, leading to different microstructure and improved gel strength of WPI in the presence of calcium lactate. © 2017 Society of Chemical Industry.

Associations of sedentary behavior and physical activity with physical measurements and dyslipidemia in school-age children: a cross-sectional study.

BACKGROUND: Physical activity and sedentary behavior are common factors influencing cardiovascular health. However, how school and leisure-time activity/sedentary behavior are associated with physical fitness and blood lipid levels in primary school children in consideration of gender disparity remains unclear. METHODS: Data was obtained from a health and nutrition survey on primary school children from nine areas in China. The association between physical activities/sedentary behaviors (school and leisure-time physical activity levels, screen time, and other sedentary behaviors) and anthropometric measurements/prevalence of dyslipidemia were examined by multilevel analysis (the individual level, class level, grade level, and investigation area level) adjusted for age, energy intake and family income. RESULTS: A total of 770 participants (average age = 9.4 ± 1.7 years) were included. Prevalence of dyslipidemia was 10.9%. Prevalence of dyslipidemia was associated with screen time in boys [OR = 3.04, 95% CI (1.24-7.45)] and inversely associated with leisure-time physical activity in boys [OR = 2.22, 95% CI (1.08-4.56)] and school-time activity in girls [OR = 5.34, 95% CI (1.18-24.16)]. CONCLUSIONS: Physical activity-but not sedentary behavior-was significantly associated with dyslipidemia in both genders. Increasing leisure-time physical activity for boys and school-time physical activity for girls may be critical.

Gender and urban-rural difference in anthropometric indices predicting dyslipidemia in Chinese primary school children: a cross-sectional study.

BACKGROUND: Childhood dyslipidemia is a critical factor of lifelong health. Therefore, screening and controlling dyslipidemia from childhood is a practical healthy strategy. However, few studies have examined the performance of anthropometric predictors of dyslipidemia in Chinese children, let alone the potential gender and urban-rural disparity. Thus, we evaluated anthropometric indices predicting dyslipidemia by genders and living areas in Chinese children. METHODS: Data were from a health and nutrition survey conducted in seven urban areas and two rural areas in China between 2011 and 2012. The serum lipid levels of the participants were compared between genders and living areas. The body mass index z-score (BMI z-score), waist-hip ratio (WHR), waist-height ratio (WHtR), and mid-upper arm height ratio (MaHtR) were used as predictors. The receiver operating characteristic (ROC) analysis was performed to investigate the ability of anthropometric indices predicting dyslipidemia. RESULTS: A total of 773 participants (average age = 9.3 ± 1.7 y) were included. The prevalence of dyslipidemia was 10.9%. Anthropometric indices were all significantly related to blood lipid profiles in boys after adjustment for age. The areas under the ROC curves (ACUs) were significantly larger than 0.5 in boys (ranged between 0.66-0.73), and were larger in rural boys (ranged between 0.68 and 0.94). MaHtR and WHR were associated with the highest specificity (93.8%) and highest sensitivity (100%), respectively. CONCLUSION: Using anthropometric indices, screening for dyslipidemia may be more appropriate in boys than in girls in China, especially in rural boys. The BMI z-score, WHR, WHtR, and MaHtR were all significantly associated with dyslipidemia in boys; using WHR and MaHtR as indicators achieved the highest sensitivity and specificity, respectively.

Complete genome sequence of Streptococcus thermophilus MN-BM-A01, a strain with high exopolysaccharides production.

Streptococcus thermophilus MN-BM-A01 (ST MN-BM-A01) (CGMCC No. 11383) was a strain isolated from Yogurt Block in Gansu, China. The yogurt fermented with this strain has good flavor, acidity, and viscosity. Moreover, ST MN-BM-A01 could produce a high level of EPS which can confer the yogurt with improved rheological properties. We reported the complete genome sequence of ST MN-BM-A01 that contains 1,876,516bp encoding 1704 coding sequences (CDSs), 67 tRNA genes and 6 rRNA operons. The genomic sequence indicated that this strain included a 35.3-kb gene cluster involved in EPS biosynthesis.

[Effects of milk with inulin and vitamin D_3 on bone health and gastrointestine symptoms in lactose intolerance population].

OBJECTIVE: To investigate the effects of milk with inulin and vitamin D3 on bone health and gastrointestinal symptoms in lactose intolerance( LI) population. METHODS: A total of 42 volunteers diagnosed as LI by breath hydrogen test were randomized into A or B group. Whole milk supplemented with inulin( 150 mg /100 g), vitamin D3( 2. 0µg /100 g), casein phosphopeptides( 5. 0 mg /100 m L), milk minerals( 40 mg /100 g), and low-lactose whole milk were given to A or B groups respectively. Bone mass density( BMD), calcium absorption and gastrointestinal symptoms were measured at the 0th and6 th week of the intervention. RESULTS: After 6 weeks, BMD increased significantly in group A( P = 0. 013). In group B, BMD also increased but the trend was not significant. Calcium absorption increased in group A but decreased slightly in group B, the trends in both groups lacked of statistic significant. Gastrointestinal symptoms were ameliorated in both groups, but still there was no significance. For all the measurements, there was nostatistic significant difference between groups. CONCLUSION: Milk with inulin and vitamin D3 could improve bone health in LI population, gastrointestinal symptoms after drinking this certain milk were analogous to low lactose milk.

Complete Genome Sequence of Streptococcus thermophilus MN-BM-A02, a Rare Strain with a High Acid-Producing Rate and Low Post-Acidification Ability.

Streptococcus thermophilus MN-BM-A02 was originally isolated from a traditional fermented dairy product in China. The characteristics of this bacterium are its high acid-producing rate and low post-acidification. This study presents the genome sequence of MN-BM-A02. Its complete genome comprises 2,025 genes and 1,850,434 nucleotides with an average G+C content of 39%.

[Prevalence of self-reported food allergy and food intolerance and their associated factors in 3 - 12 year-old children in 9 areas in China].

OBJECTIVE: To measure the prevalence and the associated factors of food allergy and food intolerance in 3 - 12 year-old children in 9 areas in China. METHOD: 1792 children selected by multistage cluster sampling method from 7 cities and 2 rural areas, from November 2011 to April 2012, with a face-to-face survey to children and their parents, and the logistic regression was used to analyze the associated factors of food allergy and food intolerance of children. RESULTS: The prevalence of self-reported food allergy and food intolerance were 8. 4% and 7. 7%, respectively. The common foods led to food allergy reported by children's parents were seafood, fish, egg, fruit and milk. The parental allergy was risk factors of food allergy of children (OR = 4. 49 (95% CI 2. 52 - 8. 01), P <0. 01). The picky eating was risk factor of food intolerance of children(OR = 2. 40(95% CI 1. 43 - 4. 02), P < 0. 01). And the education of mother was protective factor of food intolerance of children (the mother with college degree and above relative to with middle school degree and below (OR = 0. 40 (95% CI 0. 20 - 0. 80), P = 0. 01). CONCLUSION: Children' s food allergy and food intolerance were associated with genetic factors and environmental factors included parental education and family economic status. Variable foods were necessary for children' s growth and development, therefore, it is demanded to conduct intervention studies based on the associated factors.

[Effect of poor dietary behaviors on the overweight and obesity of school-aged children].

OBJECTIVE: To explore the rate of overweight and obesity, and the association between unhealthy dietary behaviors and overweight and obesity among Chinese school-aged children from 9 areas. METHODS: By multiple stage stratified cluster sampling, 814 children aged 7 - 12 years old were chosen, provided with questionnaire and anthropometric measurements. According to the definition from Working Group on Obesity in China, children,were divided into different group, univariate logistic regression and multivariate logistic regression were used to analyze the associations between unhealthy dietary behaviors and overweight and obesity. RESULTS: The rates of overweight and obesity of school-aged children were 22. 88% and 9. 90%, respectively. The rates were higher in urban areas, and second-tier cities were similar with first-tier city. Influence factor analysis revealed skipping breakfast behavior was the influence factor (OR =1. 65, P<0.05, OR= 2. 22, P <0. 01), picky eating behavior was negative correlation (OR =0.43, P<0.01 ; OR = 0. 32, P <0. 01) , and eating fact food and drinking carbonated beverage were picked out by the multivariate logistic regression model. CONCLUSION: School-aged children's overweight and obesity has been an increasingly serious health problem, which were correlated with genetic factor, environmental factor, and dietary behaviors and so on, poor dietary behavior might be influence factor for overweight and obesity, so it is necessary to provide earlier intervention strategies for parents to promote children's good dietary habits.

Detection and identification of wild yeast in Koumiss.

Koumiss is a slightly alcoholic fermented mare's milk beverage, originally obtained by using a natural mixed starter of lactic acid bacteria and yeasts. Yeast is an important component of Koumiss processing which can affect the aroma, texture, as well as the nutrients beneficial to human health, but few reports have examined the yeast ecology of local ecosystems. The purpose of this study was to isolate and identify the yeast present in Koumiss from three representative regions of China using a polyphasic method. A total of 655 yeast isolates were obtained from 96 Koumiss samples collected from three regions in China. Koumiss harbored yeast populations at 5-7 log CFU/ml. Twelve different yeast species belonging to nine genera were detected in the Koumiss samples tested, including Candida pararugosa, Dekkera anomala, Geotrichum sp., Issatchenkia orientalis, Kazachstania unispora, Kluyveromyces marxianus, Pichia deserticola, Pichia fermentans, Pichia manshurica, Pichia membranaefaciens, Saccharomyces cerevisiae and Torulaspora delbrueckii. Kluyveromyces marxianus, Kazachstania unispora and Saccharomyces cerevisiae were the dominant species present in this traditional fermented dairy product. This study is the first to identify the yeast communities associated with Koumiss in China. The results enrich our knowledge of yeast in Koumiss, give us a more complete picture of the microbial diversity in Koumiss and can be used to promote the development of the local dairy industry.