Search

The structures and physicochemical properties of ginkgo starches from seven cultivars were investigated and their relationships analyzed. The ginkgo starches had oval or irregular shapes, size distributions with a unimodal peak, and an A-type crystal pattern. The fine structures, crystalline structures, and physicochemical properties varied significantly among these ginkgo starches. Pearson correlation analysis and a PCA loading plot indicated that amylopectin A-chains and amylose had negative effects on the IR ratio, I max , and D, while amylopectin B-chains had a clear positive effect on the relative crystallinity. Furthermore, the amylopectin short B1-chains and long B-chains contributed amorphous and single-helix structures, respectively. The thermal properties of the ginkgo starches were mainly influenced by the amylopectin B-chains and I max , while the pasting properties were mainly influenced by amylopectin B-chains and helical structures. These results indicated that the starch fine structures and crystalline structures had significant effects on the physicochemical properties., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019. Published by Elsevier Ltd.)

In rice production, pre-harvest sprouting (PHS) of late ripening seeds is one of the most serious quality defects in rice grain quality. In the present study, PHS impact was investigated by examining the physicochemical properties, eating and cooking quality (ECQ) of rice grain. Four rice cultivars suffering from PHS had impaired ECQ, reduced apparent amylose content, and decreased total starch content, with an increase in total protein content. The viscosity of flours and starches prepared from the PHS grains was significantly reduced. Starch molecular structure analysis also showed remarkable decreases in the short chains of amylopectin, long amylose chains and reduced starch crystallinity of the PHS grains. Moreover, the PHS native starch tended to have low starch digestibility. This provides useful information for understanding the effects of PHS on white rice grain quality as well as on starch fine structure and its physicochemical properties., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

• The SSI allelic effects on rice grain quality profiles were investigated. • Cooked rice grains of SSIj showed higher taste values than SSIi. • SSIi restricted cooked rice grain elongation. • Starch physicochemical properties were impacted by SSI allelic variation. Near-isogenic lines Nip(Wxb / SSIj), Nip(Wxb / SSIi), Nip(wx / SSIj) and Nip(wx / SSIi) in the japonica rice Nipponbare (Nip) background containing allelic variation in the starch synthase gene SSI and Wx were investigated for cooked rice grain quality, starch morphology, pasting profiles, fine structure and crystallinity characteristics. Rice grains carrying the SSIi allele had poor cooked rice taste in the Wxb background. The introduction of SSIi caused reduced cooked rice grain elongation, especially in the wx background. Starch granule size was reduced in SSIi rice and the viscosity of flour and starch prepared from SSIi rice was markedly increased. Moreover, analysis of the starch molecular structure revealed a remarkable increase in the short amylopectin chains and reduced starch relative crystallinity compared with SSIj rice, which resulted in decreased gelatinization characteristics. These results suggest that SSI allelic variation has multiple effects on rice grain quality, as well as starch fine structure. [ABSTRACT FROM AUTHOR]

Ginkgo biloba L. is an important economic tree species in China, and its kernels have been used as a popular food in Asian countries. Herein, the morphology, basic chemical components, starch granule structures, and physicochemical properties of kernel flours from seven ginkgo cultivars were investigated, and their relationships were analyzed. The kernels were oval or spherical in shape, with variable sizes. The starch granules exhibited both regular and irregular Maltese cross patterns. Amylose was mainly distributed in amorphous growth rings. A spatial variation in the 865/942 cm−1 ratio was observed within individual starch granules. Variations in total starch content, apparent amylose content (AAC), crude protein content (CPC), total amino acid content (TAAC), starch fine structure, and thermal and pasting properties were observed among the seven kernel flours. Pearson correlation coefficients and principle component analyses showed that the thermal properties were affected by kernel CPC, TAAC, AAC, and starch fine structure, while the pasting properties were affected by AAC and starch fine structure. Furthermore, experiments showed that the seed protein structure and α-amylase activity affected the pasting properties of ginkgo kernel flours. [ABSTRACT FROM AUTHOR]