Antioxidant activity of blueberry anthocyanin extracts and their protective effects against acrylamide‐induced toxicity in HepG2 cells

In this study, the antioxidant activities of blueberry anthocyanin extracts from ten blueberry varieties were evaluated based on the methods of scavenging activities for DPPH radicals, ABTS radicals, hydroxyl radicals and ferric reducing antioxidant power (FRAP) assay. Among the ten blueberry varieties, Polaris had the highest antioxidant abilities and the largest amounts of anthocyanins identified by HPLC‐MS. The protective effects of anthocyanin extracts from Polaris (AEP) against acrylamide (AA)‐induced toxicity in HepG2 cell models were also evaluated due to the neurotoxic, genotoxic and potentially carcinogenic effects of AA. The protective effects of AEP on the damage of HepG2 cells were explored from the aspects of cell viability, T‐SOD and CAT activity and MDA level. The AEP (5, 10, 20 μg mL^?1) could significantly increase cell viability (P < 0.01) and inhibit AA‐induced cytotoxicity. Polaris also markedly promoted the activity of SOD, CAT and inhibited MDA level. The results showed that AEP had strong antioxidant activities, presenting high protective effects against AA‐induced cell damage in HepG2 cell models.     

Anti‐obesity effect of feeding probiotic dahi containing Lactobacillus casei NCDC 19 in high fat diet‐induced obese mice

Nowadays, studies about the anti‐obesity potential of probiotics are of growing interest. Lactobacilli are one of the well‐studied probiotics owing to their preventing effect on metabolic disorders. This study was undertaken to access the anti‐obesity effect of probiotic dahi containing Lactobacillus casei NCDC 19 on C57BL/6 mice. Feeding of probiotic dahi showed reduce body weight gain and epididymal fat weights. Moreover, blood glucose, plasma lipids and expression level of leptin were reduced and caecal bifidobacteria counts and adiponectin expression levels were significantly increased. It can be concluded that feeding of probiotic dahi containing L. casei NCDC 19 showed potential anti‐obesity effects.     

Effect of pH on the formation of serum heat‐induced protein aggregates in heated yak milk

Serum heat‐induced protein aggregates at various pH levels were isolated from heated yak milk by size‐exclusion fast protein liquid chromatography. Analysis by reversed‐phase high‐performance liquid chromatography showed that β‐lactoglobulin and κ‐casein were the two main proteins in these aggregates. The amount of serum heat‐induced protein aggregates increased from pH 6.6 to 7.4, whereas the content of β‐lactoglobulin in aggregates decreased from 61.9% at pH 6.6 to 50.4% at pH 7.2, and then increased to 51.3% at pH 7.4. The content of κ‐casein, αs₁‐casein and β‐casein increased from pH 6.6 to pH 7.4. These results show that serum heat‐induced protein aggregates are pH dependent.     

‘Lipase and protease production of dairy Penicillium sp. on milk‐protein‐based solid substrates’

The lipolytic and proteolytic activity of Penicillium camemberti PC TT033 and Penicillium roqueforti PR G3, cultured on the whey solids or simulated cheese media, were compared under several pH reaction conditions. Lipolytic activity was higher when both strains had been cultured on the whey medium than on the simulated cheese medium, whereas proteolytic activity was less influenced by the culture medium. The relationship between the reaction pH and these enzyme activities was dependent on the culture medium, which suggested that the expression level and balance of isozyme rely on the culture substrate.     

In vitro antioxidant and in vivo xanthine oxidase inhibitory activities of Pandanus amaryllifolius in potassium oxonate‐induced hyperuricemic rats

Xanthine oxidase (XO) plays an important role in the regulation of uric acid and prevents it from being overproduced as in hyperuricemia disease. The combined effects of antioxidant and xanthine oxidase inhibitor would become a promising approach for hyperuricemia treatment. In this research, the antioxidant and xanthine oxidase inhibitory activities of Pandanus amaryllifolius leaf were evaluated. The leaf water extract (PA‐W) showed highest total phenols, and petroleum ether extract (PA‐PE) showed highest total flavonoids contents. The antioxidant activity of DPPH, metal chelating and hydrogen peroxide was highest in PA‐W extract. The treatment of PA‐W extract at 1000 mg kg^?1 body weight in potassium oxonate‐induced hyperuricemic rats showed significant (P < 0.001) decrease in serum uric acid level by 85% and XO activity by 64%, respectively, as compared to the hyperuricemic rats. In conclusion, the P. amaryllifolius possess the dual effect of antioxidant and XO inhibition as potential therapeutic agents in the hyperuricemia treatment.     

Thermo‐rheological and functional properties of gamma‐irradiated wholewheat flour

The effects of different doses (0, 0.5, 1, 2.5, 5 and 10 kGy) of gamma irradiation on the thermal, rheological and functional properties of the wholewheat flour were evaluated. Water and oil absorption capacity of the flour increased from 85.92% to 91.44% and 1.10 to 1.91 g g^?1 of flour, respectively, with increase in irradiation dose. The dough development time decreased with dose from 4.0 to 3.0 min. The transition temperatures (T_o, T_p and T_c) decreased as the dose increased; enthalpy of gelatinisation (?H) decreased from 5.18 to 4.27 J g^?1 with dose. The flow behaviour showed a shear‐thinning behaviour, and the hysteresis area decreased with dose. The structural recovery decreased with dose. FTIR did not show formation of any new chemical groups.     

Physicochemical properties of ready‐to‐eat extruded nixtamalized maize‐based snacks enriched with grasshopper

The aim of this research was to prepare an extruded snack based on nixtamalized maize flour (Zea mays L.) (NMF) enriched with grasshopper meal (Sphenarium purpurascens Ch.) (GM) using a single screw extruder with a compression screw ratio of 3:1. A central experimental design comprising three independent variables, namely, extrusion temperature (T = 120–180 °C), feed moisture content (FMC = 18–22 g/100 g) and the grasshopper meal proportion (GMP = 0–40 g/100 g), was used. Increasing T decreased (P < 0.05) the expansion index (EI), bulk density (BD) and hardness (H). Increasing the FMC increased (P < 0.05) the EI. Increasing the GMP decreased (P < 0.05) the EI, H and water absorption index (WAI) and increased (P < 0.05) the BD and total colour difference (ΔE). The treatments that resulted in better general acceptability were those that contained a lower GMP. An extruded snack acceptable to the consumer can be obtained from a blend of NMF and GM, and up to 8.11 g/100 g of GM can be incorporated without affecting the physicochemical properties and acceptance of the snack.