The Composition, Structure, and Functionalities of Prolamins from Highland Barley.

The composition, structure, and functionalities of prolamins from highland barley were investigated. These parameters were compared with those of the commonly applied prolamins (zein). There are more charged and hydrophilic amino acids in highland barely prolamins than zein. The molecular weight of highland barely prolamins was between 30 and 63 kDa, which was larger than that of zein (20 and 24 kDa). The main secondary structure of highland barely prolamins was ß-turn helices, while α-helical structures were the main secondary structure in zein. The water holding capacity, thermal stability, emulsifying capacity, and stability of prolamins from highland barley were significantly higher than in zein, while the opposite results were observed for oil absorption capacity between the two. The diameter of fibers prepared using highland barely prolamins was almost six times that of zein, while highland barely prolamins formed ribbon structures instead of fibers. Therefore, the results provide guidance for applications of prolamins from highland barley.

Effect of konjac glucomannan on aggregation patterns and structure of wheat gluten with different strengths.

Konjac glucomannan (KGM) can act as a food additive to improve the quality of dough. The effects of KGM on the aggregation patterns and structural properties of weak, middle, and strong gluten were studied. We found that with a higher proportion of KGM substitution (10%), the aggregation energy of middle and strong gluten became lower than the control samples, while exceeding the control for weak gluten. With 10% KGM, aggregation of glutenin macropolymer (GMP) was enhanced for weak gluten, but suppressed for middle and strong gluten. The α-helix transferred to ß-sheet in weak, but caused more random-coil structures for middle and strong gluten induced by 10% KGM. With 10% KGM, the network for weak gluten became more continuous, but severely disrupted for middle and strong gluten. Thus, KGM has distinct effects on weak, middle, and strong gluten, which related to the alteration of gluten secondary structures and GMP aggregation pattern.