Inhibitory effects of litchi (Litchi chinensis Sonn.) flower-water extracts on lipase activity and diet-induced obesity

Litchi flower–water extract (LFWE) contains plenty of phenolic acids, flavonoids, condensed tannins, anthocyanins, and proanthocyanidins. In this study, we used eight male rats per group that were assigned randomly to one of the following dietary group: (1) normal-caloric diet and distilled water; (2) hypercaloric diet (HCD) and distilled water; (3) HCD and 2.5% LFWE; (4) HCD and 5% LFWE for 10 weeks. As results, LFWEs demonstrated a suppressive (p < 0.05) effect on in vitro lipase activities; meanwhile, larger sizes of livers, perirenal and epididymal adipose tissues, and cell sizes of epididymal adipose tissues in hypercaloric-diet-fed group were decreased (p < 0.05) by drinking LFWEs, especially in 5% LFWE-treated groups. Increased (p < 0.05) serum cholesterol and liver lipid levels were measured in hypercaloric-diet-fed rats. However, drinking LFWEs also decreased (p < 0.05) those levels to that similar to the NCD group, whereas drinking LFWEs resulted in higher (p < 0.05) faecal lipid concentrations. It also corresponded to the liver TNF-α and IL-1β values which were ameliorated (p < 0.05) in hypercaloric-diet-fed rats with LFWEs. Therefore, the result of this investigation match the anticipation, which LFWE indeed possesses a potential nutraceuticals for anti-obesity effects.     

Antioxidative and anti-inflammatory effects of polyphenol-rich litchi (Litchi chinensis Sonn.)-flower-water-extract on livers of high-fat-diet fed hamsters

Gentisic acid and epicatechin are two major compounds in phenolic acids and flavonoids of litchi-flower-water extracts (LFWEs), respectively. Increased (p < 0.05) serum lipids and liver size/lipid, damage/inflammatory indices, TBARS value, CRP level, MMP-9 activity, and decreased (p < 0.05) liver GSH and TEAC levels, and SOD, CAT and GSH-Px activities were observed in high-fat-diet fed hamsters compared to normal-fat-dietary hamsters. Those biochemical values of high-fat-diet fed hamsters were significant improved (p < 0.05) by drinking LFWEs. In addition, these improvements on liver damage induced by a high-fat diet were also evidenced in the histopathological examination of livers where less microvesicular steatosis and no necrotic/inflammatory cells were observed in high-fat-diet fed hamster drinking LFWEs. Therefore, protective effects of LFWEs on liver damage of high-fat-diet fed hamsters can be accounted for antioxidative properties and anti-inflammatory effects of LFWEs.     

Antrodia camphorata ameliorates high-fat-diet induced hepatic steatosis via improving lipid metabolism and antioxidative status

Nonalcoholic fatty liver disease (NAFLD) commonly results from excessive dietary fat intake which characterized by obesity and insulin resistance. Wild fruiting body of Antrodia camphorata (AC) was assayed for alleviative effects on NAFLD. An NAFLD animal model was successfully established in male 7-week-old C57BL/6 mice fed with high-fat diet (HFD) for 36 weeks. The HFD mice exhibited obese and impaired glucose metabolism. After an induction of NAFLD syndrome, AC was given for one week via gavage. Mice with AC treatment showed lowered (p < 0.05) serum TG and TC, lowered (p < 0.05) liver TG content, improved (p < 0.05) oxidative status (TBARS values and GSH levels), and ameliorated (p < 0.05) liver damage (AST, ALT, and LDH values). In addition, AC activated (p < 0.05) gene expressions of PPAR-α with its downstream genes in the liver and caused higher (p < 0.05) rectal temperature, which showed AC attenuates hepatic lipid accumulation by promoting lipid oxidation and further suggests the role of AC in energy expenditure. Overall, our findings revealed that AC possesses alleviative effect on NAFLD.     

Acting to self-regulate unhealthy eating habits. An investigation into the effects of habit,hedonic hunger and self-regulation on sugar consumption from confectionery foods

Many people are motivated to eat healthily but find it difficult to override established and less healthy habits. Habits by their nature are unconscious and cued by the environment, thus making them powerful determinants of behaviour. Limited research has explored the role of habit as a mediator between self-regulation and sugar consumption. This study investigated the relative importance of factors that support/impede the consumption of foods with high sugar content and the mediating effect of habit. The study sample was 500 Irish adult’s representative of the population. Sugar consumption, habit, hedonic hunger, self-efficacy, perceived need, dietary planning and dietary self-monitoring were assessed using self-reported measures. A path analysis of the data was used to test the direct and indirect effects of the independent factors on estimated sugar consumption grams per day (g/d). In addition, the interaction effects of self-efficacy and dietary planning/self-monitoring on sugar consumption was examined using simple slope analysis. The results showed that habit had the largest effect in the model and was positively related to sugar consumption g/d (b = 12.09, p < 0.01). While the direct effect of self-efficacy on sugar-consumption g/d was significant (b = −5.25, p < 0.05), this effect was partially mediated by habit (−4.84, Bca CI −7.00, −3.00) and the direct effect of action control on sugar consumption (b = −1.30, p = 0.311) was fully mediated by habit (b = −2.42, Bca CI −3.93, −1.20), which indicates that strong unhealthy habits compete against self-efficacy and can reduce the potential benefits of dietary planning and self-monitoring. The simple slope analysis revealed that action control has a significant negative effect on sugar intake when self-efficacy is weak (b = −5.48, p = 0.01). The direct effect of hedonic hunger on confectionery sugar consumption (b = 1.38, p = 0.376) was fully mediated by habit (b = 5.92, Bca CI 4.20, 8.08) indicating that the desire to eat tempting food may overrides one’s intended behaviour resulting in counter-intentional habits. It is apparent from the findings that a dual strategy of targeting behaviour and the underlying habits may be effective in improving dietary intake and self-regulation is likely to be sustainable only in an environment that facilitates healthy eating behaviour.     

Effects of a black rice extract (Oryza sativa L. indica) on cholesterol levels and plasma lipid parameters in Wistar Kyoto rats

This study was designed to evaluate the efficacy of an anthocyanin pigmented rice (e.g. black rice) to mitigate the onset of hypercholesterolemia in rats-fed atherogenic diets. Male Wistar (n = 10/group) rats were fed with atherogenic diets containing 0.5% cholesterol in the presence and in the absence of bile salt (e.g. 0.05% cholic acid) along with a standardized black rice extract (BRE) (e.g. 3%, w/w). All animals were individually housed in stainless steel cages and fed with the experimental diets during a 12-h period for 10 weeks. Body weights of rats were measured every week of the experiment. After 10 weeks fed on experimental diets, rats were sacrificed and plasma total cholesterol, HDL and LDL cholesterol and triacylglycerols were measured immediately. The total cholesterol (TC) content in the liver, heart and aorta, and the concentration of triacylglycerol (TAG) were measured after lipid extraction using Folch method. Rats fed with 0.5% cholesterol containing diets which also included bile salt exhibited a considerably more severe hypercholesterolemia than counterparts fed diets containing only 0.5% cholesterol. The inclusion of the BRE in diets significantly (p < 0.05) decreased the level of TC, LDL–TC and TAG in plasma of rats-fed control diets that either contained or were absent in bile salt (p < 0.05). There were no differences in HDL-level. Liver crude lipids and total cholesterol levels were also significantly (p < 0.05) decreased in experimental groups relative to the control group in both experiments. Thus, supplementation of atherogenic experimental diets with BRE effectively decreased lipid levels in hypercholesterolemic rats. In lieu of the mixture of bioactive components present in BRE, it is possible that more than one mechanism underlying this reduction in lipids is involved.     

Hepatoprotective effect of peptic hydrolysate from salmon pectoral fin protein byproducts on ethanol-induced oxidative stress in Sprague–Dawley rats

Bioactive peptides were generated by pepsin hydrolysis from salmon pectoral fin protein byproduct, and the hepatoprotective effect of the peptic hydrolysate (PH) on ethanol-induced oxidative stress was investigated in Sprague–Dawley rats. Administration of ethanol for 4 weeks significantly (p < 0.05) increased serum markers of liver damage, such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase; however, these activities decreased significantly (p < 0.05) after PH administration. Elevated thiobarbituric acid reactive substance levels in liver tissue and serum decreased significantly (p < 0.05) following administration of PH. Ethanol exposure significantly (p < 0.05) decreased glutathione contents in liver and serum, and hepatic antioxidant enzyme activities such as superoxide dismutase and glutathione peroxidase, while the PH treatment significantly (p < 0.05) increased these altered parameters. These results indicate that the PH had a protective effect against ethanol-induced hepatotoxicity that was comparable to that of silymarin, which was supported by evaluating liver histopathology in the rats.     

Antiobesity and lipid lowering effects of theaflavins on high-fat diet induced obese rats

Theaflavins are major polyphenols in black tea. This study investigated antiobesity and lipid lowering effects of black tea extract (BTE), a highly purified theaflavins mixture (TFs, 83.84%) and theaflavin (TF1, 93.25%) on high-fat diet (HFD) induced obese rats. The body weight was slightly reduced by BTE and TFs (p > 0.05), and was significantly decreased by TF1 (p < 0.05) relative to the HFD control group. All samples remarkably decreased the food intake, adiposity index and the serum levels of total cholesterol (TC), triacylglycerol (TG) and low-density lipoprotein cholesterol (LDL-C) (p < 0.05), except that BTE and TF1 insignificantly decreased the TC concentration (p > 0.05). Moreover, administration of BTE, TFs and TF1 all significantly decreased atherogenic index (AI), enhanced insulin sensitive index (ISI), inhibited the hepatic lipase (HL) activity (p < 0.05), and slightly reduced leptin level in liver, decreased serum alanine transaminase (ALT) activity and increased serum superoxide dismutase (SOD) activity (p > 0.05) as compared to that of the HFD controls. These results indicated that theaflavins were one of the functional components which contributed to the antiobesity and lipid lowering effects of black tea, and might reduce the risk of type 2 diabetes and cardiovascular disease (CVD) in obese patients.     

Protective effect of a litchi (Litchi chinensis Sonn.)-flower-water-extract on cardiovascular health in a high-fat/cholesterol-dietary hamsters

Cardiovascular disease (CVD) is the major cause of death in the developed countries. Litchi-flower-water-extract (LFWE) contains plenty of phytochemicals, i.e. phenols, flavonoids, tannins which may own cardio-protection. Ten male hamsters per group were assigned randomly to one of the following dietary groups: chow diet and normal distilled water (LFCD/NDW); high-fat/cholesterol diet and normal distilled water (HFCD/NDW); HFCD and 2.5% litchi-flower-water-extract (HFCD/2.5% LFWE); HFCD and 5% LFWE (HFCD/5% LFWE). Serum lipids, cardiac index, and hepatic lipids were lowered (p < 0.05) in high-fat/cholesterol-dietary hamsters by drinking 2.5% and 5% LFWE which may result from higher (p < 0.05) LDL receptor and peroxisome proliferator-activated receptor-alpha (PPAR-α) gene expressions and lower (p < 0.05) fatty acid synthase (FAS) gene expression, as well as increased (p < 0.05) faecal lipid and bile acid excretions. Drinking LFWE also lowered (p < 0.05) serum malondialdehyde (MDA) contents in high-fat/cholesterol-dietary hamsters, and even showed the same (p > 0.05) serum MDA contents as the LFCD/NDW group’s which could be due to increased (p < 0.05) serum trolox equivalent antioxidant capacity (TEAC). Therefore, this study indicated that LFWE indeed characterises a protective effect on cardiovascular health in vivo.     

Influence of genotype and environment on the dietary fiber content of field pea (Pisum sativum L.) grown in Canada

The insoluble fiber (IDF), soluble fiber (SDF) and total dietary fiber (TDF) contents of six field pea (Pisum sativum L.) genotypes from five growing locations in Saskatchewan in the 2006 and 2007 growing seasons were analyzed to investigate the possible effect of genotype, environment and year on fiber content. Samples were analyzed using the enzymatic–gravimetric method of fiber analysis. Growing location had a significant effect (p < 0.0001) on IDF, SDF and TDF content. Genotype had a strong effect (p < 0.0001) on both IDF and TDF content, while having no significant effect (p = 0.40) on SDF content. Crop year displayed a significant effect on SDF and TDF (p < 0.0001) content while having a smaller effect on IDF content (p < 0.01). Green cotyledon genotypes exhibited significantly higher IDF and TDF contents (p < 0.05) than did yellow genotypes. Significant genotype × location (p < 0.05) and location × year (p < 0.001) interaction terms were observed for TDF content.     

Wild bitter gourd increased metabolic rate and up-regulated genes related to mitochondria biogenesis and UCP-1 in mice

The effects of bitter gourd (Momordica charantia, BG) on metabolic rate, mRNA expressions of UCP-1, genes related to mitochondria biogenesis and glucose homeostasis were investigated. C57BL/6J male mice were fed modified AIN-93G diets supplemented without (the Basal group) or with 5% (w/w) lyophilized BG powder (the BGP group) for 22 weeks. The BGP group had higher O₂ consumption, CO₂ production and respiratory quotient in the dark phase (p < 0.05) measured at 5th week. Compared to the Basal group, the BGP group had lower body weight and adipose mass, higher mRNA of UCP1, PGC-1α and NrF1 in white adipose tissue (p < 0.05), PGC-1α and NrF1 or tfam in skeletal muscle and brown adipose tissue (p < 0.05) and better glucose homeostasis. These results imply that BGP might increase mitochondria biogenesis and metabolic rate, which may lead to less fat accumulation and contribute, at least in part, to the improved control of glucose homeostasis.     

The in vivo antioxidant and antifibrotic properties of green tea (Camellia sinensis,Theaceae)

The in vivo antioxidant and antifibrotic properties of green tea (Camellia sinensis, Theaceae) were investigated with a study of carbon tetrachloride (CCl₄)-induced oxidative stress and hepatic fibrosis in male ICR mice. Oral administration of green tea extract at doses of 125, 625 and 1250 mg/kg for 8 weeks significantly reduced (p < 0.05) the levels of thiobarbituric acid-reactive substances (TBARS) and protein carbonyls in the liver by at least 28% compared with that was induced by CCl₄ (1 mL/kg) in mice. Moreover, green tea extract administration significantly increased (p < 0.05) the activities of catalase, glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in the liver. Our study found that oral administration of green tea extract prevented CCl₄-induced hepatic fibrosis, as evidenced by a decreased hydroxyproline level in the liver and a reduced incidence of hepatic fibrosis by histological observations. These results indicate that green tea exhibits potent protective effects against CCl₄-induced oxidative stress and hepatic fibrosis in mice by inhibiting oxidative damage and increasing antioxidant enzyme activities.     

Diet-induced changes in alginate- and laminaran-fermenting bacterial levels in the caecal contents of rats

Brown algae contain soluble polysaccharides, such as alginic acid, fucoidan and laminaran. To assess the induction of dietary fiber-fermenting bacteria in the intestine, rats were fed diet containing no dietary fiber (control) or 2% w/w of the polysaccharides for 2 weeks. The levels of dietary fiber-fermenting bacteria in caecal contents were determined using decimal dilution culture containing 1% w/v of the fibers. Caecal microbiota in the rats was analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). In the culture method, 4–9 log viable cells/g caecal content of alginate-fermenting bacteria was detected in rats fed alginate, while this was not detected in rats fed the control diet. Although laminaran-fermenting bacteria were detected in control rats (4–9 log viable cells/g), the level observed in rats fed laminaran was 8 or 9 log viable cells/g. On the other hand, fucoidan-fermenting bacteria were not detected in rats fed fucoidan. DGGE analysis showed laminaran administration increased the diversity of bacterial bands. Clostridium spp. and Parabacteroides distasonis were detected as typical species in rats fed alginate and laminaran. The results indicate that the intake of soluble fermentable fibers in edible brown algae can alter the intestinal microbiota and its fermentation capacity.     

Cholesterol lowering and vascular protective effects of ethanolic extract of dried fruit of Crataegus pinnatifida,hawthorn (Shan Zha), in diet-induced hypercholesterolaemic rat model

Consumption of functional foods for managing plasma cholesterol level has gained acceptance globally. The hypocholesterolaemic and vascular protective effects of the dried fruit of Crataegus pinnatifida, hawthorn (Shan Zha), were investigated in rats fed with normal diet, high cholesterol diet (HCD) or HCD plus Shan Zha 80% ethanolic extract treatment (30 or 100 mg/kg/day, p.o.) for 4 weeks. Shan Zha extract markedly reversed the increased plasma total cholesterol and high density lipoprotein cholesterol induced by HCD with a dose-dependent improvement on the atherogenic index. It also demonstrated good hepatoprotective function by reducing lipid content in the liver. The blunted endothelium-mediated aortic relaxation in HCD-fed rats was restored by high dosage of Shan Zha extract treatment. The current results showed that Shan Zha extract could provide its cholesterol lowering effect by up-regulating hepatic CYP7A1 mRNA expression which leads to enhanced bile acid biosynthesis. It is postulated that the hypocholesterolaemic effect is the primary beneficial effect given by Shan Zha extract; it then leads to other secondary beneficial effects such as vascular protective and hepatoprotective functions. Thus, Shan Zha extract could provide an overall improvement on the hepatic and vascular systems that may be important in relieving hypercholesterolaemia-related complications.     

Flavanoid rich ethyl acetate fraction of Musa paradisiaca inflorescence down-regulates the streptozotocin induced oxidative stress,hyperglycaemia and mRNA levels of selected inflammatory genes in rats

Musa paradisiaca inflorescence is a commonly used vegetable. The purpose of this study was to evaluate the antioxidant; hypoglycaemic and anti-inflammatory activities of flavanoid rich fraction of M. paradisiaca inflorescence (MPIF) in streptozotocin (STZ) induced diabetes mellitus. Diabetic rats were treated with MPIF (200 mg/kg body weight/day) for 60 days. Diabetic rats showed significant (p < 0.05) increase in blood glucose, HbA₁C and lipid peroxidation products (LPO) and reduction in the activities of antioxidant enzymes in liver. The activities of inflammatory markers COX-2 and 5-LOX in monocytes and mRNA expressions of NF-κB, TGF-β₁, TNF-α and IL-6 in liver were significantly (p < 0.05) increased in diabetic group. In addition, the histopathological analysis of liver showed that severe steatosis and inflammation in diabetic group. But all these parameters were significantly (p < 0.05) reduced to near normal level and restored the histopathological alterations in MPIF treated group. In addition, HPLC and ESI-MS analysis of MPIF revealed that the presence of gallic acid (4.49 g%), quercetin (1.13 g%) and epicatechin. This indicates that the supplementation of MPIF may be beneficial as food supplement for the prevention or attenuation of diabetic complications.     

Preventive effects of caffeic acid on lipids,lipoproteins and glycoproteins in isoproterenol induced myocardial infarcted rats

Dietary phenolic compound intake has been reported inversely related to the incidence of cardiovascular diseases. The aim of this research was to understand the preventive effects of caffeic acid, a phenolic acid on lipids, lipoproteins and glycoprotein components in isoproterenol induced myocardial infarcted rats. Rats were pretreated with caffeic acid (15 mg/kg body weight) daily for a period of 10 days. After pretreatment, rats were induced myocardial infarction by subcutaneous injection of isoproterenol (100 mg/kg body weight). Isoproterenol induced myocardial infarcted rats showed significant (P < 0.05) decreased levels of heart phospholipids and significant (P < 0.05) increased levels of serum and heart cholesterol, triglycerides, free fatty acids and serum phospholipids. Isoproterenol also significantly (P < 0.05) increased low density and very low density lipoprotein cholesterol and significantly (P < 0.05) decreased high density lipoprotein cholesterol levels. The activity of liver 3-hydroxy-3methyl glutaryl-coenzyme-A-reductase was significantly (P < 0.05) increased and lecithin cholesterol acyl transferase activity was significantly (P < 0.05) decreased in isoproterenol induced myocardial infarcted rats. In addition, the levels of glycoprotein components in the serum and heart were significantly (P < 0.05) increased in myocardial infarcted rats. Pretreatment with caffeic acid positively altered all the above mentioned biochemical parameters studied in isoproterenol induced myocardial infarcted rats.In conclusion, caffeic acid protected the rat's heart from the deleterious effects of lipids, lipoproteins and glycoproteins by its antilipidemic and antiglycative effects in isoproterenol induced myocardial infarcted rats. A diet containing caffeic acid may be beneficial to myocardial infarction.     

Effect of the ripening time under vacuum and packaging film permeability on processing and quality characteristics of low-fat fermented sausages

The effect of vacuum ripening of low-fat fermented sausages packaged in films with different permeabilities on their microbiological, physicochemical and sensorial characteristics was studied. High-fat control sausages were produced with 30% initial fat and low-fat sausages with 10% initial fat. The low-fat sausages were separated into: (a) non-packaged (control) and (b) packaged under vacuum on 7th, 12th and 17th day of processing, remaining under vacuum during the ripening period for 21, 16 and 11 days, respectively, in three different oxygen (100, 38 and ⩽ 5 cm³/m²/24 h/1 atm) and water vapour (4.5, <2.5 and 1 g/m² 24 h) permeability plastic bags. Vacuum packaging reduced (p < 0.05) the weight loss, the hardness and extent of lipid oxidation in the sausages, increased (p < 0.05) their lightness, but had no effect (p > 0.05) on the redness, compared to the control sausages. Packaging low-fat fermented sausages under vacuum for the last 11 days of ripening in packaging film with high permeability increased (p < 0.05) the lactic acid bacteria count. The same product packaged in film with medium permeability had a higher (p < 0.05) Micrococcaceae count and the same (p > 0.05) hardness and overall acceptability as the high-fat control sausages. A ripening time of 11 days and the medium packaging film permeability were the most appropriate conditions for the vacuum packaging of low-fat fermented sausages.     

Porcine artery elastin preparation reduces serum cholesterol level in rats

The effect of porcine artery elastin on serum cholesterol level was investigated in rats fed a cholesterol-free diet. Rats were fed for 4 weeks, with a diet (ED) containing 15% casein and 5% of porcine artery elastin in comparison with a diet (CD) containing 20% casein. The total serum and non-HDL-cholesterol concentrations were lower (P < 0.001) in ED-fed group than the CD-fed group at the end of the experiment. Caecal propionate concentration and Bifidobacterium and Lactobacillus population were higher (P < 0.05) in ED-fed group than the CD-fed group. The results of this study suggest that porcine artery elastin could be considered as a functional dietary protein with hypocholesterolaemic ability. Favourable amino acid composition and lysine derived cross links may at least be partially responsible for the hypocholesterolaemic ability of ED. Moreover, the higher caecal propionic acid concentration in the ED-fed group may have suppressed the cholesterol synthesis in the liver, and reduced the serum cholesterol level.     

Correlations between climatic conditions and foodborne disease

Climate change is likely to affect the incidence of foodborne disease outbreaks, but the relationship between foodborne disease and conditions of climate change is still poorly understood and may vary regionally. Therefore, this study investigated the relationship between climatic conditions/seasonal changes, with regards to temperature and relative humidity, and the incidence of foodborne disease outbreaks in South Korea during 2003–2012. Eight pathogens commonly associated with foodborne diseases were identified and the effect of changes in temperature and relative humidity on each of them was investigated. Pathogenic Escherichia coli had the strongest correlation with temperature and relative humidity (0.8998, 0.8803, p < 0.001), followed by Vibrio parahaemolyticus (0.6964, 0.8048, p < 0.05), Campylobacter jejuni (0.6595, 0.6142, p < 0.05), Salmonella spp. (0.7531, 0.3893, p = 0.005, 0.211), and Bacillus cereus (0.3556, 0.2040, p > 0.05). Norovirus had a strong negative correlation with temperature and relative humidity (− 0.9791, − 0.8747, p < 0.001), followed by Clostridium perfringens (− 0.6457, − 0.8635, p < 0.05). Staphylococcus aureus poorly correlated with both temperature and relative humidity (0.1106, − 0.1169, p > 0.05). The statistical model in the present study could be useful for estimating the prospective effects of climate change on foodborne disease patterns.     

Concentration of soybean isoflavones by nanofiltration and the effects of thermal treatments on the concentrate

An investigation was performed on the profile and the content of isoflavones in the concentrate of aqueous Defatted Soy Flour (DSF) extract obtained by nanofiltration. The effect of thermal treatments on these isoflavones was also evaluated according to a Central Composite Design (CCD 2^k) with varying temperatures (70 to 90 °C) and times (15 to 45 min). Through nanofiltration it was possible to concentrate β-glucosides and malonyl glucosides (p < 0.05) in aqueous DSF extract but it was not possible to concentrate aglycones (p > 0.05). The thermal treatments applied on the concentrate showed that the malonyl glucosides were influenced by temperature (p < 0.05), while the β-glucosides were influenced not only by temperature but also by the time of interaction of the factors investigated (p < 0.05). Moreover, there was no alteration in the contents (p > 0.05) of aglycone or total isoflavones.     

Features and performance of edible films,obtained from whey protein isolate formulated with antimicrobial compounds

The goal of this research effort was to assess the efficacy of edible films produced from whey protein isolate (WPI) and glycerol, including incorporation of lactic acid (LA) and propionic acid (PRO), chitooligosaccharides with nominal MW of 3 kDa (COS) and natamycin (NA) as antimicrobial agents. Their features were evaluated in vitro via agar diffusion and viable cell counting, against spoilage microflora often found contaminating cheese surfaces. The effect of incorporating the aforementioned compounds upon thickness, moisture content (MC), solubility (S), density (ρ^s), water activity (a_w) and water vapor permeability (WVP), as well as upon tensile and optical properties of those films were also evaluated. Films formulated with LA, PRO or COS exhibited antimicrobial activity against all microorganisms tested, yet the viable cell count assay was more sensitive and reproducible. COS was the most active against Gram-negative bacteria, whereas LA was the most active against Gram-positive ones. NA was not active against bacteria, but displayed the strongest effect against yeasts. Incorporation of said antimicrobial compounds did not significantly (p > 0.05) affect film thickness, yet it significantly (p < 0.05) reduced tensile strength (TS). Incorporation of LA and NA in particular did not significantly (p < 0.05) affect MC, S, ρ^s, WVP, elongation at break (EB) and Young's modulus (YM) values; however, a statistically significant increase (p < 0.05) of MC, S and WVP, together with a statistically significant decrease (p < 0.05) of ρ^s were attained upon incorporation of PRO or COS. Moreover, PRO produced the highest variation (p < 0.05) in EB, TS and YM, whereas COS produced the highest change (p < 0.05) in optical properties.