Effect of drying methods on physicochemical properties and in vitro hypoglycemic effects of orange peel dietary fiber

Abstract

Dietary fiber plays an important role in the prevention and reduction of chronic diseases. This study evaluated the effect of drying methods (hot air drying, vacuum drying, and freeze‐drying) on physicochemical properties and in vitro hypoglycemic effects of soluble and insoluble dietary fiber from orange peels. Freeze‐drying significantly decreased the bulk density of the soluble and insoluble dietary fiber and increased the viscosity of soluble dietary fiber solutions (36.33 mPa s). Hot air drying caused a decrease in the molecular weight of soluble dietary fiber compared with freeze‐drying. Freeze‐dried dietary fibers exhibited a higher glucose adsorption capacity and glucose dialysis retardation index than fibers from other drying conditions, and this method enhanced the inhibitory effect of dietary fiber on α‐amylase activity. Based on these results, freeze‐drying is suggested for use in dietary fiber processing to obtain high‐quality products for use in functional foods. Practical applications When formulating fiber‐rich food products, the functional properties of dietary fiber must be considered. The functional properties depend on the processing conditions and physicochemical properties of the fiber. The results show that freeze‐drying has significant advantages in improving physicochemical properties and in vitro hypoglycemic effects of dietary fiber, and the application of freeze‐drying in dietary fiber processing could enhance its nutrient and commercial values.

Effects of Ultrasound and Steam Explosion Treatments on the Physicochemical Properties of Rice Bran Fibre

“…This finding is partly in agreement with the results reported by Y. Liu et al (2017), who also observed shrinkage of the soluble fraction but, at the same time, found the formation of the porous structure on the insoluble fraction of orange peel fibre after freeze-drying. The difference was likely due to the different types of dietary fibre used in the two studies, and heat treatments were given to the fibre.…”

“…Moreover, BD has reportedly been influenced by drying methods such as oven drying or freeze-drying (Y. Liu et al, 2017). Therefore, the bulk density of freeze-dried untreated unpurified RB (untreated FD) was analysed to remove the possibility that the reduction in BD is an effect of drying.…”

Physicochemical Properties of Kakamut Gum (<i>Acacia polyacantha</i>) and Hashab Gum (<i>Acacia senegal</i>): A Comparative Analysis

“…Dry matter is what remains after the greater part of the water is evaporated out of Gum. Dry matter is an indicator of the amount of nutrients that are accessible to utilize [32]. The result demonstrates that the percentage of dry matter of Kakamut and Hashab Gums were within the ranges between (91.92 ̶ 89.03%) respectively, these outcomes fell within the international specifications [33].…”

Impact of drying methods on the physicochemical properties and nutritional composition of defatted black soldier fly ( Hermetia illucens ) pre‐pupae flour

“…Liu et al. (2017) reported that the freeze‐dried products reduces the insoluble fiber and density of the fiber particle. The ash content was also recorded the significant difference in the FD BSFP and SD BSFP flour ( p < .05) with 9.81 and 12.04 percentage, respectively (Table 2).…”

“…The increased fiber and ash content noted in both the FD and SD BSFP flours may be due to the feed substrate (Shumo et al, 2019), which contains high amount of carbohydrate and fiber. Liu et al (2017) reported that the freeze-dried products reduces the insoluble fiber and density of the fiber particle. The ash content was also recorded the significant difference in the FD BSFP and SD BSFP flour (p < .05) with 9.81 and 12.04 percentage, respectively (Table 2).…”