Components of wheat flour as activator of commercial enzymes for bread improvement

Bioactive proteins in bovine colostrum and effects of heating, drying and irradiation

Bovine colostrum (BC) contains bioactive proteins, such as immunoglobulin G (IgG), lactoferrin (LF) and lactoperoxidase (LP). BC was subjected to low-temperature, long-time pasteurization (LTLT, 63 °C, 30 min) or high-temperature, short-time pasteurization (HTST, 72 °C, 15 s) and spray-drying (SD), with or without γ-irradiation (GI, ∼14 kGy) to remove microbial contamination. Relative to unpasteurized liquid BC, SD plus GI increased protein denaturation by 6 and 11%, respectively, increasing to 19 and 27% after LTLT and to 48% after HTST, with no further effects after GI (all P < 0.05). LTLT, without or with GI, resulted in 15 or 29% denaturation of IgG, compared with non-pasteurized BC, and 34 or 58% for HTST treatment (all P < 0.05, except LTLT without GI). For IgG, only GI, not SD or LTLT, increased denaturation (30-38%, P < 0.05) but HTST increased denaturation to 40%, with further increases after GI (60%, P < 0.05). LTLT and HTST reduced LP levels (56 and 81% respectively) and LTLT reduced LF levels (21%), especially together with GI (47%, P < 0.05). Denaturation of BSA, β-LgA, β-LgB and α-La were similar to IgG. Methionine, a protective amino acid against free oxygen radicals, was oxidised by LTLT + GI (P < 0.05) while LTLT and HTST had no effect. Many anti-inflammatory proteins, including serpin anti-proteinases were highly sensitive to HTST and GI but preserved after LTLT pasteurization. LTLT, followed by SD is an optimal processing technique preserving bioactive proteins when powdered BC is used as a diet supplement for sensitive patients.

Mineral Composition and Baking Value of the Winter Wheat Grain under Varied Environmental and Agronomic Conditions

The mineral composition of cereal crops, the technological value of grain and flour, as well as bread quality are affected by the genotype, environment, and agronomic management practices. The aim of the research has been to investigate the effect of the environment and agronomic factors on the mineral composition and baking value of winter wheat grain. Opal cultivar grain of the genetically determined prime-quality wheat was obtained in a two-year field experiment (varied soil and weather). The agronomic management practices included tillage (conventional moldboard-plow, reduced ploughless, and strip-till) and nitrogen fertilisation rate (100 kg·N·ha−1, 200 kg·N·ha−1). In the grain samples, the content of macronutrients was assayed: P, K, Mg, Ca, and Na, total protein, and wet gluten as well as sedimentation value. The colour and the water absorption of flour and its content of protein and ash were determined. Laboratory baking was performed. It was found that the content of protein and gluten in grain, sedimentation value, bread volume, and weight changed depending on the environmental conditions and research years. Tillage and nitrogen rate, despite an effect on the properties of grain and flour, did not differentiate, however, the bread quality. The environmental conditions and agronomic management practices did not have a significant effect on the content of mineral nutrients in grain, except for calcium. The biofortification with mineral nutrients in prime-quality winter wheat cultivar grain by selecting the environmental and agronomic conditions seems more difficult than increasing the content of organic compounds and enhancement of flour and bread parameters.

Antioxidant and antibacterial activities of bioactive peptides in buffalo's yoghurt fermented with different starter cultures

The effect of Lactobacillus acidophilus 20552 ATCC (T2) or Lactobacillus helveticus CH 5 (T3) in combination with yoghurt starter (1:1) on the antioxidant and antibacterial activities of the bioactive peptides present in buffalo's yoghurt was studied. The SDS-PAGE results indicate that all caseins were completely hydrolyzed by both strains, whereas whey protein fractions were still present. All starter cultures have the ability to produce low-molecular-weight bioactive peptides, most of which were originated from β-casein and fewer from αs₁ casein. The antioxidant activity (%) of the water-soluble peptide extract from yoghurt samples increased in all samples during storage. Samples containing Lb. helveticus CH 5 showed the highest values. All yoghurt treatments displayed antibacterial activity against Escherichia coli. Control yoghurt and T3 showed higher antibacterial activity on E. coli, Staphylococcus aureus, and Bacillus cereus as compared to T2.