Chemical Composition, Quality Parameters, Exopeptidase and Oxidoreductase Activity Changes During Temporal Development of Wheat Grain Infestation by Sitophilus granarius

Abstract

Changes in chemical composition, grain quality parameters, oxidoreductase and exopeptidase activities of wheat grains infested by Sitophilus granarius were monitored during 1 year of storage. Significant increase in flour titratable acidity of infested grains occurred by day 90. Subsequently, infestation was followed by decrease of grain hectoliter weight on day 180, decrease of carboxypeptidase activity on day 240, polyphenol oxidase and catalase activities increased and total starch decreased on day 270, while significant changes of total protein content, extractable protein concentration, phenylalanyl-aminopeptidase and Zeleny sedimentation occurred between 300 and 360 days of storage. The data indicate that S. granarius infestation influenced chemical composition, quality parameters, as well as oxidoreductase and exopeptidase activity in wheat grains, but the extent of these changes was mostly detectable at higher levels of grain infestation. Among the examined parameters, flour titratable acidity and carboxypeptidase activity showed potential to be used as early indicators of grain infestation. PRACTICAL APPLICATIONSGranary weevil, S. granarius, is one of the major grain-damaging insects. This primary infester feeds on grains as adult, or on grain endosperm as larvae causing significant economic losses, due to unsuitability of damaged grains for human food production. Although various methods of S. granarius detection in stored grains have been applied worldwide, there is still a need for cheap indicative methods for detecting insect infestation. This study investigating changes in chemical composition, quality parameters, oxidoreductase and exopeptidase activities during temporal development of infestation by S. granarius shows that flour titratable acidity and carboxypeptidase activity could be used as early indicators of wheat grain infestation. bs_bs_banner Journal of Food Biochemistry ISSN 1745-4514

Effects of refrigeration on biochemical, digestibility, and technological parameters of carioca beans during storage

“…However, inadequate control of factors affecting grain quality at this postharvest stage impairs the nutritional quality and technological and sensory properties of the grains, thus, reducing the commercial value (Ferreira et al, , ; Siqueira et al, ; Tulyathan & Leeharatanaluk, ; Ziegler, Ferreira, Hoffmann, Chaves, et al, ). Among the factors that affect grain quality during the storage period are moisture and grain temperature, temperature and relative humidity of the air in the storage environment, quality of the grains shortly after harvesting, and presence of insects (Nasar‐Abbas et al, ; Njoroge et al, ; Pohndorf, Meneghetti, Paiva, Oliveira, & Elias, ; Rani, Chelladurai, Jayas, White, & Kavitha‐Abirami, ; Strelec, Šarkanj, Mrša, & Ugarcic‐Hardi, ). Controlling these factors provides the lowest rates of metabolic activity in the grains during storage, and lower is the respiratory rate, lower is the consumption of energy reserves, representing their better conservation (Chidananda et al, ).…”

“…. Among the factors that affect grain quality during the storage period are moisture and grain temperature, temperature and relative humidity of the air in the storage environment, quality of the grains shortly after harvesting, and presence of insects (Nasar-Abbas et al, 2009;Njoroge et al, 2015;Pohndorf, Meneghetti, Paiva, Oliveira, & Elias, 2018;Rani, Chelladurai, Jayas, White, & Kavitha-Abirami, 2013;Strelec, Šarkanj, Mrša, & Ugarcic-Hardi, 2013). Controlling these factors provides the lowest rates of metabolic activity in the grains during storage, and lower is the respiratory rate, lower is the consumption of energy reserves, representing their better conservation (Chidananda et al, 2014).…”

Biochemical and Quality Parameter Changes of Wheat Grains during One-Year Storage under Different Storage Conditions

“…For determination of the extractable protein content and activity of oxidoreductive and proteolytic enzymes, it was necessary to extract proteins and enzymes from differently stored grains. Extractions were performed by Strelec et al [28]. Extractable protein content was determined using the Bradford method [29] with bovine serum albumin as standard.…”

“…Carboxypeptidase activity was determined using the colorimetric method using N-carbobenzyloxy-L-phenylalanyl-leucine (CBZ-Phe-Leu) as substrate and picrylsulfonic acid as hydrolysis product coupler, according to Waters et al [32]. Aspartic proteinase activity was measured using 2% (w/v) Hb as substrate according to Voigt et al [33] with some modification previously reported by Strelec et al [28]. Catalase activity was determined using a colorimetric assay using a catalase assay kit (Sigma, USA).…”

Armazenamento de sementes de café submetidas à secagem a pleno sol em terreiro suspenso e à secagem por ventilação forçada à sombra

“…Essas diferenças são atribuídas à perda ou ganho de umidade durante as etapas de expurgo, catação manual de sementes brocadas e tratamento com fungicida. Devido à sua higroscopicidade, as sementes são propensas à troca de umidade com o ar circundante (Strelec et al, 2010). Apesar disso, os teores de água permaneceram próximos aos teores de água final após a secagem.…”