The effect of malting on phenolic compounds and radical scavenging activity in grains and breakfast cereals.

Breakfast cereals are popular grain foods and sources of polyphenols. Malting alters polyphenol content and activity; however, effects are varied. The total polyphenol content (TPC), radical scavenging activity (RSA), and polyphenol profile were analyzed in unmalted and malted grains (wheat, barley, and sorghum) and breakfast cereals (wheat, barley) by Folin Ciocalteu Reagent (FCR), % inhibition of the free radical 2,2-diphenyl-1-picryl-hydrazyl, and high performance liquid chromatography. Higher TPC was observed in all malted grains and breakfast cereals compared with unmalted samples (p < 0.05). Higher RSA was also observed in all malted samples compared to unmalted samples (p < 0.05) except for wheat grain to malted wheat grain. In this study, malting induced additional polyphenols and antioxidant activity in grains and cereal products. Malted grain breakfast cereals may be practical sources of polyphenol antioxidants. PRACTICAL APPLICATION: This study utilized malting in a unique way to investigate potential health benefits of polyphenols and antioxidant activity in grains (wheat, barley, and sorghum) and ready-to-eat breakfast cereals (wheat and barley). This study found that grains and breakfast cereals are important sources of antioxidant polyphenols, and these were significantly increased in malted varieties. Understanding this is important as grains and breakfast cereals are widely consumed staple foods. Consuming healthier grain products may be a practical strategy in reducing the risk of noncommunicable diseases such as colorectal cancer and type-2 diabetes, where wholegrain consumption may be important in prevention.

Anti-salmonella properties of kefir yeast isolates: An in vitro screening for potential infection control.

The rise of antibiotic resistance has increased the need for alternative ways of preventing and treating enteropathogenic bacterial infection. Various probiotic bacteria have been used in animal and human. However, Saccharomyces boulardii is the only yeast currently used in humans as probiotic. There is scarce research conducted on yeast species commonly found in kefir despite its claimed potential preventative and curative effects. This work focused on adhesion properties, and antibacterial metabolites produced by Kluyveromyces lactis and Saccharomyces unisporus isolated from traditional kefir grains compared to Saccharomyces boulardii strains. Adhesion and sedimentation assay, slide agglutination, microscopy and turbidimetry assay were used to analyze adhesion of Salmonella Arizonae and Salmonella Typhimurium onto yeast cells. Salmonella growth inhibition due to the antimicrobial metabolites produced by yeasts in killer toxin medium was analyzed by slab on the lawn, turbidimetry, tube dilution and solid agar plating assays. Alcohol and antimicrobial proteins production by yeasts in killer toxin medium were analyzed using gas chromatography and shotgun proteomics, respectively. Salmonella adhered onto viable and non-viable yeast isolates cell wall. Adhesion was visualized using scanning electron microscope. Yeasts-fermented killer toxin medium showed Salmonella growth inhibition. The highest alcohol concentration detected was 1.55%, and proteins with known antimicrobial properties including cathelicidin, xanthine dehydrogenase, mucin-1, lactadherin, lactoperoxidase, serum amyloid A protein and lactotransferrin were detected in yeasts fermented killer medium. These proteins are suggested to be responsible for the observed growth inhibition effect of yeasts-fermented killer toxin medium. Kluyveromyces lactis and Saccharomyces unisporus have anti-salmonella effect comparable to Saccharomyces boulardii strains, and therefore have potential to control Salmonella infection.

Salmonella infection - prevention and treatment by antibiotics and probiotic yeasts: a review.

Global Salmonella infection, especially in developing countries, is a health and economic burden. The use of antibiotic drugs in treating the infection is proving less effective due to the alarming rise of antibiotic-resistant strains of Salmonella, the effects of antibiotics on normal gut microflora and antibiotic-associated diarrhoea, all of which bring a growing need for alternative treatments, including the use of probiotic micro-organisms. However, there are issues with probiotics, including their potential to be opportunistic pathogens and antibiotic-resistant carriers, and their antibiotic susceptibility if used as complementary therapy. Clinical trials, animal trials and in vitro investigations into the prophylactic and therapeutic efficacies of probiotics have demonstrated antagonistic properties against Salmonella and other enteropathogenic bacteria. Nonetheless, there is a need for further studies into the potential mechanisms, efficacy and mode of delivery of yeast probiotics in Salmonella infections. This review discusses Salmonella infections and treatment using antibiotics and probiotics.

Effects of malted and non-malted whole-grain wheat on metabolic and inflammatory biomarkers in overweight/obese adults: a randomised crossover pilot study.

Metabolic dysfunction in obesity may be attenuated by whole-grain intake, which has been attributed to synergistic actions of bioactive compounds. Germination/malting may increase grain bioactives, including polyphenols, however biological effects compared with non-germinated grains are unclear. Polyphenols and biological effects were compared between malted-wheat (MLT) and whole-grain wheat (CON) breakfast cereals. Polyphenol content and antioxidant activity were significantly higher (P<0.01 and P<0.05, respectively) in MLT. Corresponding obesity-related biomarkers were measured in 10 overweight/obese adults in a 2×4-week double-blind, randomised, crossover trial. Following both interventions, diastolic blood pressure reduced significantly with time (P<0.05) and low-density lipoprotein increased slightly (P<0.05) over time. A significant time*cereal effect (P<0.05) was found for insulin resistance, decreasing following CON and increasing with MLT. No other significant metabolic or inflammatory differences were found. Whilst MLT contained significantly increased polyphenols, cumulative effects in attenuating obesity-related metabolic dysfunction may require increased consumption.

Effects of dietary cottonseed oil and tannin supplements on protein and fatty acid composition of bovine milk.

This experiment was conducted to determine the effects of diets supplemented with cottonseed oil, Acacia mearnsii-condensed tannin extract, and a combination of both on composition of bovine milk. Treatment diets included addition of cottonseed oil (800 g/d; CSO), condensed tannin from Acacia mearnsii (400 g/d; TAN) or a combination of cottonseed oil (800 g/d) and condensed tannin (400 g/d; CPT) with a diet consisting of 6·0 kg dry matter (DM) of concentrates and alfalfa hay ad libitum, which also served as the control diet (CON). Relative to the CON diet, feeding CSO and CPT diets had a minor impact on feed intake and yield of lactose in milk. These diets increased yields of milk and protein in milk. In contrast to the TAN diet, the CSO and CPT diets significantly decreased milk fat concentration and altered milk fatty acid composition by decreasing the proportion of saturated fatty acids but increasing proportions of monounsaturated and polyunsaturated fatty acids. The CPT diet had a similar effect to the CSO diet in modifying fatty acid profile. Overall, reduction in milk fat concentration and changes in milk fatty acid profile were probably due to supplementation of linoleic acid-rich cottonseed oil. The TAN diet had no effect on feed intake, milk yield and milk protein concentration. However, a reduction in the yields of protein and lactose occurred when cows were fed this diet. Supplemented tannin had no significant effect on fat concentration and changes in fatty acid profile in milk. All supplemented diets did not affect protein concentration or composition, nitrogen concentration, or casein to total protein ratio of the resulting milk.

Activity of endogenous muscle proteases from 4 Australian underutilized fish species as affected by ionic strength, pH, and temperature.

Storage conditions may influence the hydrolytic activity of endogenous muscle enzymes postmortem, rate of autolysis of myofibrillar proteins, and biological properties of hydrolyzed end products. This study investigated the effect of ionic strength, pH, and temperature on the activity of endogenous calpain-like, cathepsins B and B+L measured in crude extract obtained from deepwater flathead, silver warehou, ribaldo, and ribbonfish muscles. Activity of calpain-like enzymes in 3 examined species was significantly higher at pH 6.5 than pH 6.0 or 5.5. Raising the reaction temperature increased (P < 0.05) calpain-like activity in ribaldo. Endogenous activity of cathepsin B in ribbonfish and silver warehou declined significantly with increasing ionic strength at pH 6.5 to 6.0. The obtained results will further expand our understanding of the impact that postmortem storage conditions have on the activity of endogenous fish proteases with respect to quality and bioactivity of fish proteins and potentially diversify utilization of underutilized fish species.

Rheological properties and sensory characteristics of set-type soy yogurt.

The study examined chemical composition and rheological and sensory properties of probiotic soy yogurt during 28 day storage at 4 degrees C. Soymilk supplemented with 2% (w/v) inulin or 1% (w/v) each of raffinose and glucose was used as a base for soy yogurt manufacture. Viability of probiotic organisms and their metabolic activity measured as production of organic acids and aldehyde content responsible for beany flavor, as well as rheological and sensory properties of soy yogurt, were examined. Inulin or raffinose/glucose supplementation in soymilk increased the bacterial population by one log cycle and the amount of lactic acid. Probiotic bacteria metabolized more aldehyde than yogurt culture and substantially reduced the beaniness in soy yogurt as determined by sensory evaluation. The probiotic soy yogurts showed more viscous and pseudoplastic properties than the control soy yogurts, but the sensory evaluation results showed preference for the control soy yogurts which were slightly less viscous. Control soy yogurt provided better mouth feel than probiotic soy yogurts.