Influences of pretreatment and drying methods on composition, micro/molecular structures and some health‐related functional characteristics of dietary fibre powder from orange pulp residues

Abstract

Summary Influences of pretreatment methods (washing, blanching, soaking in ethanol), drying methods (hot air‐drying, infrared‐drying, microwave‐drying) and drying temperature on selected characteristics of dietary fibre powder from orange pulp residues were investigated. Pretreatments improved the hydration properties, oil‐holding capacity and glucose dialysis retardation index, but led to losses of fibres, decreased α‐amylase inhibitory activity and aflatoxin B1 adsorption capacity. Hydration properties, oil‐holding capacity and glucose uptake depended on the structure and porosity of the fibre, while the ability to inhibit α‐amylase and AFB1 adsorption depended more on the content and molecular fingerprinting of the fibre. Drying condition did not significantly affect functional properties of the fibre, except for the ability to uptake glucose, inhibit α‐amylase and adsorb AFB1 (P ≤ 0.05). Hot air‐drying at 60 °C resulted in fibre with the highest ability to decrease the rate of glucose and AFB1 adsorption.

Evaluation of antioxidant properties of extractable and nonextractable polyphenols in peel and flesh tissue of different peach varieties

“…Overwhelming epidemiological and clinical investigations have repeatedly shown the apparent association between high fruit intake and the decreased incidence of cardiovascular and other chronic diseases (Borbal an, Zorro, Guill en, & Barroso, 2003;Kris-Etherton et al, 2002). Natural antioxidants such as vitamins, carotenes, minerals, or fiber are not supposed to be the only components responsible for the antioxidant properties of fruit (Chuyen, Roach, Golding, Parks, & Nguyen, 2017;Sungsinchai, Niamnuy, Jaree, & Devahasti, 2017). In previous research, the significant correlations have been reported between phenolic contents and antioxidant capacities (Su et al, 2017;Zhuang, Ma, Guo, & Sun, 2017).…”

Applicability of vacuum-microwave drying for tomato fruit based on evaluations of energy cost, color, functional components, and sensory qualities

“…Microwave drying (MD) is a relatively inexpensive method in which dipole heating causes water to migrate toward the product surface (Salimi Hizaji, Maghsoudlou, & Jafari, ). A higher drying rate is expected for the MD process compared to other drying processes because microwave energy can rapidly penetrate the inner layer of a dried sample (Sungsinchai, Niamnuy, Jaree, & Devahastin, ). The absorbed energy is then converted into heat, causing a rapid temperature increase and hence an accelerated drying rate (Therdthai & Zhoui, ).…”

Effects of different moisture contents on the structural and functional properties of cellulose with cell wall components in different citrus fibres

“…Higher agglomeration and a less dense fibre network reduce the WRC and subsequent rheological properties. Agarwal et al (2018), 29 Sungsinchai et al (2017) 23 and Eyholzer et al (2010) 38 have found that the WRC is inversely proportional to the fibre aggregation that occurs during the drying processes such as oven drying and vacuum drying. 38…”

“…1,4,19 The pre-treatment conditions of the citrus fibres are important for controlling their size, shape, composition, and functionality. 23 Pre-treatment involves a process flow of acid hydrolysis, bleaching, washing, filtration, and drying. 18 The process of acid hydrolysis starts with breaking the glycosidic linkages within the amorphous regions since solvents such as water and acid penetrate the amorphous regions.…”

“…20,27 Washing with water and alcohol reduces the free sugars and allows for increased movement and retention of water. 18,23,28 Sungsinchai et al (2017) 23 found that drying at 60 °C increased the ability of the fibres to hold water. Pectins have been shown to decrease after washing and drying, which has been observed to increase the viscoelastic behaviour of the citrus fibres.…”