Changes in protein size distribution during wheat flour cake processing

The immune-enhancing effect and in vitro antioxidant ability of different fractions separated from Colla corii asini

In this study, Colla corii asini (CCA) was fractionated into three fractions with different molecular weights using ultracentrifugation equipment. Components with a molecular weight of >10 kDa in F1 accounted for 81.90%, whereas that in F2 and F3 was 15.63% and 0.94%, respectively. The immunomodulatory activity of CCA fractions was investigated using RAW264.7 cell model and their antioxidant abilities were evaluated by 2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and ferric-reducing antioxidant power (FRAP) assay. The results indicated that RAW264.7 cells treated with F1 released the highest level of nitric oxide, reactive oxygen species, interleukin-6, and tumor necrosis factor-α. The ABTS and FRAP value of F1 were 65.81% and 29.33 μM TE/L, respectively, which were 22.53%, 128.44% and 43.72%, 132.16% higher than that of F2 and F3, respectively. These results suggested that components with a molecular weight of >10 kDa in CCA had stronger immunomodulatory and antioxidant ability, which would help develop the health food based on CCA. PRACTICAL APPLICATIONS: Colla corii asini (CCA) is a famous protein-based traditional Chinese medicine and nutritional supplement. During the processing of CCA, the molecular weight (MW) of CCA collagen components changed dynamically due to the protein aggregation, degradation, and the Maillard reaction. Some studies have shown that the MW distribution of CCA was not uniform. However, the MW range of CCA components which has strong antioxidant and immunomodulatory activity is still not clear, and few studies have reported the mechanism of CCA's immunomodulatory activity and active ingredients. Therefore, it is important to figure out the characteristics of CCA components with stronger immunomodulatory and antioxidant ability, such as the MW distribution and chemical composition of CCA fractions. And this study will be great for the processing of CCA products which has better biological functions.

Replacement of animal proteins in food: How to take advantage of nutritional and gelling properties of alternative protein sources

Given the growing world population, there is a need to balance animal and vegetable sources of dietary protein and to limit overall protein resources, and food formulation has to consider alternative protein sources as a way to meet human requirements. The protein concentration, essential amino acids (EAA) of all protein sources were analyzed with respect to human needs along with additional macronutrients of nutritional and energy interest (i.e. carbohydrates and lipids). New indexes are proposed to classify the alternative protein sources considering their EAA balance and how it may change during food processing. A global overview of all protein sources is provided including the quantity of food and associated caloric intakes required to fulfill our daily protein needs. As texture is a key parameter in food formulation, and is often influenced by protein gelation, we conducted an exhaustive review of the literature in a large scientific database on the ability of proteins from all sources to go through the sol-gel transition with the corresponding physical-chemical conditions. Traditional and innovative recipes are discussed and some improvement are proposed in terms of their ability to fulfill human needs for EAA and food and caloric intakes.

Effect of the order of incorporation of cake ingredients on the formation of batter and the final properties: contribution of the addition of pea flour

The investigation dealt with the effect of the replacement of a part of wheat flour by pea flour on the properties of batters and cakes. As the protein composition of pea flour differs from that of wheat, the effect of its incorporation on batter formation and cake properties was monitored throughout the different steps of cake processing. The incorporation of air, which influences the cell structure and density of the cake, was the subject of particular attention. Four orders of incorporation were first investigated to identify their effects on a standard recipe made with 100% wheat flour. Mixing first egg and sugar together allows introducing air, but most of it is lost after oil and flour introduction. Whatever the order of incorporation, the density of the batter ends around 1.1 ± 0.2 g.cm^-1. However, batter consistencies are significantly different and resulting cakes show different crumb structures. These results are discussed in terms of physicochemical mechanisms, and a schematic representation of the phenomena occurring at the different steps of mixing depending on the order of ingredient incorporation is proposed. When 20 and 40% of the wheat flour was replaced by pea flour using the two most energy-efficient orders of incorporation, more air was incorporated into the batter. However, the resulting cakes were denser, but surprisingly softer. Differences in cell structure explain this apparent contradiction.

Effects of tempering with steam on the water distribution of wheat grains and quality properties of wheat flour

In this study, the effects of tempering with steam on the water distribution of wheat grains and the microbial load in wheat flour were investigated, as well as the physicochemical properties of wheat flour. Results showed that when steam treatment time was 320 s, the total plate count (TPC), yeast and mold count (YMC), and mesophilic aerobic spores (MAS) in flour decreased by 1.74, 1.99 and 1.01 lgCFU/g, respectively. Nuclear magnetic resonance (NMR) results showed that tempering with steam accelerated the water distribution of grains and significantly (p < 0.05) shortened the tempering time. Moreover, flour yield, particle size, ash content, and damaged starch content of flour were all altered. Furthermore, after tempering with steam, proteins were aggregated and starches were partially gelatinized, which caused dough development time and stability of flour increasing. Collectively, our findings indicated steam tempering could shorten the tempering time and improve the qualities of flour partly.

Deacetylation of 3-acetyl-deoxynivalenol in wheat flour is mediated by water-soluble proteins during the making of Chinese steamed bread

To find the determining factors for 3-acetyl-deoxynivalenol (3-ADON) deacetylation during wheat-based food production, wheat flours with different heat treatments, different matrixes of the starch-gluten mixture, and different protein fractions (Osborne classification) were evaluated. The deacetylation behavior of 3-ADON was significantly suppressed for heat-treated wheat flours, indicating that heating induced change of the functional or chemical properties of wheat grain components, especially for proteins. Among the different matrixes, only 3% of the 3-ADON in starch was converted to DON, however, this value reached 60-75% for wheat flour. The results showed that proteins were responsible for the deacetylation of 3-ADON. After separation, only albumins mediated the deacetylation of 3-ADON into DON in four protein fractions. The proteins were identified by LC-MS/MS, and the results suggested that cytochrome P450, acetylesterase and histone deacetylase were the potential targeted enzymes that mediated the deacetylation of 3-ADON during dough preparation for wheat-based food production.

Effect of heat treatment to sweet potato flour on dough properties and characteristics of sweet potato-wheat bread

The effect of heat treatment at 90, 100, 110 and 120 ℃ for 20 min to sweet potato flour on dough properties and characteristics of sweet potato-wheat bread was investigated. The lightness (L*) and a* of sweet potato flour samples after heat treatment were increased, while the b* were decreased significantly, as well as the particle size, volume and area mean diameter ( p < 0.05). A slight change of the microstructures of sweet potato flour was observed, where the number of irregular granules increased as the temperature increased from 90 to 120 ℃. Compared with sweet potato flour samples without heat treatment and with heat treatment at 90, 100 and 120 ℃, the gelatinization temperature and enthalpy change of sweet potato flour at 110 ℃ were the lowest, which were 77.94 ℃ and 3.67 J/g, respectively ( p < 0.05). After heat treatment, gas retention of the dough with sweet potato flour increased significantly from 1199 ml without heat treatment to 1214 ml at 90 ℃ ( p < 0.05). In addition, specific loaf volume of sweet potato-wheat bread with sweet potato flour after heat treatment increased significantly, which was the largest at 90 ℃ (2.53 cm3/g) ( p < 0.05). Thus, heat treatment at 90 ℃ to sweet potato flour could be potentially used in wheat bread production.