Complexation between burdock holocellulose nanocrystals and corn starch: gelatinization properties, microstructure, and digestibility in vitro

Holocellulose nanocrystals (hCNCs), with hydrodynamic diameters (DZ) ranging from about 600 to 200 nm, were prepared by treating burdock insoluble dietary fiber (IDF) with enzymes and ultrasonic power. It was...

A Modified Brewing Procedure Informed by the Enzymatic Profiles of Gluten-Free Malts Significantly Improves Fermentable Sugar Generation in Gluten-Free Brewing

The mashing step underpins the brewing process, during which the endogenous amylolytic enzymes in the malt, chiefly β-amylase, α-amylase, and limit dextrinase, act concurrently to rapidly hydrolyze malt starch to fermentable sugars. With barley malts, the mashing step is relatively straightforward, due in part to malted barley’s high enzyme activity, enzyme thermostabilities, and gelatinization properties. However, barley beers also contain gluten and individuals with celiac disease or other gluten intolerances should avoid consuming these beers. Producing gluten-free beer from gluten-free malts is difficult, generally because gluten-free malts have lower enzyme activities. Strategies to produce gluten-free beers commonly rely on exogenous enzymes to perform the hydrolysis. In this study, it was determined that the pH optima of the enzymes from gluten-free malts correspond to regions already typically targeted for barley mashes, but that a lower mashing temperature was required as the enzymes exhibited low thermostability at common mashing temperatures. The ExGM decoction mashing procedure was developed to retain enzyme activity, but ensure starch gelatinization, and demonstrates a modified brewing procedure using gluten-free malts, or a combination of malts with sub-optimal enzyme profiles, that produces high fermentable sugar concentrations. This study demonstrates that gluten-free malts can produce high fermentable sugar concentrations without requiring enzyme supplementation.

Comparison of Morphological and Physicochemical Properties of a Floury Rice Variety upon Pre-Harvest Sprouting

Pre-harvest sprouting (PHS) severely reduces rice grain yield, significantly affects grain quality, and leads to substantial economic loss. In this study, we aimed to characterize the physicochemical properties and processing quality of the Garumi 2 flour rice variety under PHS conditions and compare them with those of the Seolgaeng, Hangaru, Shingil, and Ilpum rice varieties and the Keumkang wheat variety. Analysis of the molecular structure of starch revealed uniform starch granules, increased proportions of short-chain amylopectin in DP 6–12 (51.0–55.3%), and enhanced crystallinity (30.7–35.7%) in rice varieties for flour compared with the Ilpum cooking rice variety. PHS significantly altered the starch structure and gelatinization properties of Garumi 2. It also caused surface pitting and roughness in Garumi 2 starch granules and decreased their crystallinity. Collectively, the findings of this study provide important novel insights into the effects of PHS on the physicochemical properties of Garumi 2 floury rice for flour.

Effect of dandelion root polysaccharide on pasting, gelatinization, rheology, structural properties and in vitro digestibility of corn starch

The influence of dandelion root polysaccharide (DRP) on gelatinization properties and in vitro digestibility of corn starch was investigated. Pasting behaviors indicated that the addition of DRP led to an increase of...

Properties of High-Swelling Native Starch Treated by Heat–Moisture Treatment with Different Holding Times and Iterations

Tapioca and potato starches were used to investigate the effect of heat–moisture treatment (HMT; 95–96 °C, 0–60 min, 1–6 iterations) on gelatinization properties, swelling power (SP), solubility and pasting properties. Tapioca starch had similar content and degree of polymerization of amylose, but a higher amylopectin short/long chain ratio, to potato starch. After HMT, the gelatinization temperature range was narrowed for tapioca starch, but was widened for potato starch. Decreases in SP and solubility were less for tapioca than potato starches, coinciding with a progressive shift to the moderate-swelling pasting profile for tapioca but a drastic change to the restricted-swelling profile for potato. Moreover, decreasing extents of SP and maximum viscosity for HMT tapioca starch were, respectively, in the range of 47–63% and 0–36%, and those of HMT potato starch were 89–92% and 63–94%. These findings indicate that the granule expansion and viscosity change of starch during gelatinization can be tailored stepwise by altering the HMT holding time and iteration.