Gelatinization or Pasting? The Impact of Different Temperature Levels on the Saccharification Efficiency of Barley Malt Starch

Abstract

Efficient enzymatic hydrolysis of cereal starches requires a proper hydrothermal pre-treatment. For malted barley, however, the exact initial temperature is presently unknown. Therefore, samples were micro-mashed according to accurately determined gelatinization and pasting temperatures. The impact on starch morphology, mash viscometry and sugar yields was recorded in the presence and absence of an amylase inhibitor to differentiate between morphological and enzymatic effects. Mashing at gelatinization onset temperatures (54.5–57.1 °C) led to negligible morphological and viscometric changes, whereas mashing at pasting onset temperatures (57.5–59.8 °C) induced significant starch granule swelling and degradation resulting in increased sugar yields (61.7% of upper reference limit). Complete hydrolysis of A-type and partial hydrolysis of B-type granules was achieved within only 10 min of mashing at higher temperatures (61.4–64.5 °C), resulting in a sugar yield of 97.5% as compared to the reference laboratory method mashing procedure (65 °C for 60 min). The results indicate that the beginning of starch pasting was correctly identified and point out the potential of an adapted process temperature control.

Selected Physicochemical, Thermal, and Rheological Properties of Barley Starch Depending on the Type of Soil and Fertilization with Ash from Biomass Combustion

“…The term gelatinization describes the process of melting the pseudocrystalline areas of amylopectin, accompanied by partial washing out of the amylose fraction and loss of microscopic birefringence, which can be imaged using polarized light microscopy. Typically, the gelatinization process is described using the modern method of differential scanning calorimetry (DSC) [ 42 , 43 ]. According to Xie et al [ 27 ], gelatinization properties of starch depend on the size of starch granules, the content of non-starch substances, the formation of amylose–lipid complexes, and the structure of amylopectin [ 27 ].…”

“…This is accompanied by significant leaching of amylose. At the beginning of the pasting process, a significant increase in viscosity is observed [ 42 , 43 ]. The starch gelatinization process is illustrated by a number of parameters such as gelatinization temperature (PT), maximum viscosity (PV), which shows the swelling of starch before its breakdown, and BD, which is a measure of the decrease in viscosity during storage at an elevated temperature.…”

Chemical Components, Antioxidant Activity, and Glycemic Response Values of Purple Sweet Potato Products

“…This quick reaction from the enzymes resulted in the fast increment of blood glucose level. Thus, foods with complete starch gelatinization have high glycemic response [39].…”

Effects of laccase and cellulase on saccharification of barley malt

“…When beer production is large-scale and collectivized to a certain extent, the key to improve the economic benefit of brewers is still the production technology ( Bongaerts et al., 2021 ; Florian et al., 2006 ; Wu et al., 2016 ). Because barley malt is the main material and one of the main production costs in beer production ( Rittenauer et al., 2021 ), the key to decrease beer production cost is to reduce the consumption of barley malt or improve the saccharification of barley malt. Replacing part of barley malt with rice, barley, cocoa pulp, wheat and other starch materials can decrease the cost of materials in beer production ( Nunes et al., 2020 ; Steiner et al., 2012 ), but the replacement affects the quality of malt wort and beer ( Okada et al., 2008 ).…”