Quality evaluation of probiotics enriched Chinese yam snacks produced using infrared‐assisted spouted bed drying

Abstract

A novel infrared‐assisted spouted bed drying (IRSBD) was adopted in this work to produce probiotics enriched Chinese yam snacks with high quality. The effects of drying temperature (30°C, 40°C, 50°C, 60°C, and 70°C) and airflow speed (16, 19, 22, 25, and 28 m/s) on drying characteristics, probiotics retention as well as storage stability and physical‐chemical qualities of yam snacks were studied. Results showed that the higher drying temperature and higher airflow speed were beneficial to shorten the drying time. Drying conditions had great effects on the polysaccharide yield, color, sensory quality, and storage stability of dried yams. Based on weighted comprehensive scoring, the product scores ranged from −1.092 to 0.647 were obtained. The optimal drying parameters for probiotics enriched Chinese yams were drying temperature of 40°C and airflow speed of 22 m/s. Under this condition, the probiotics could remain above 1 × 106 CFU/g for 42 days. Practical applications The healthy snack foods enriched with probiotics can meet consumers’ health demands, providing intestinal protection for people. In order to keep probiotics active, freeze‐drying are generally used but with high cost. IRSBD is an innovative combined drying technology based on infrared drying (IRD) and spouted bed drying (SBD) to overcome the nonuniform infrared heating of IRD and enhance the thermal efficiency of SBD. It was employed to dehydrate probiotics enriched Chinese yam, the products with best quality and storage stability were achieved under conditions that drying temperature of 40°C and airflow speed of 22 m/s. IRSBD provides a potential method for producing dried and probiotics enriched fruit and vegetable snacks with high‐quality.

Fruit and vegetable snacks as carriers of probiotics and bioactive compounds: a review

“…Some tubers such as Chinese yam or yacon have also recently been used as new carriers for probiotics. Li et al (2021b) applied novel infrared-assisted jet bed drying (IRD) to produce probiotic Chinese yam snacks, which is a kind of medicinal and edible product in China. Different drying temperatures (from 30 to 70 °C) and airflow speeds (from 16 to 28 m s À1 ) were evaluated, best results being obtained at 40 °C and an airflow speed of 22 m s À1 .…”

Infrared‐assisted spouted bed drying of Chinese yam cubes: effect of constant and variable temperature drying processes on drying behavior, uniformity, and quality attributes

“…Uniform drying is provided by the thorough mixing of the materials produced by the jet fluidization while the energy consumption is reduced by the efficient heating assisted with IR. In our previous work, IRSBD was used for different agricultural products, which improved dried products' quality and reduced energy consumption 13,14 . Regarding the effect of temperature and airflow rate of IRSBD, studies have shown that drying temperature is a key factor in determining drying efficiency and product quality.…”

“…In our previous work, IRSBD was used for different agricultural products, which improved dried products' quality and reduced energy consumption. 13,14 Regarding the effect of temperature and airflow rate of IRSBD, studies have shown that drying temperature is a key factor in determining drying efficiency and product quality. An increase in drying temperature leads to an improvement in drying efficiency but its effect on product quality is uncertain.…”

Something to chew on: technological aspects for novel snacks

“…apple 108,111–114 and strawberry 35 ) and tubers (e.g. yam) 115 . Probiotics were mostly incorporated by impregnation (soaking food pieces in a probiotic solution) at atmospheric pressure 35,108,113 or under vacuum 112,115 prior to drying.…”

“…yam) 115 . Probiotics were mostly incorporated by impregnation (soaking food pieces in a probiotic solution) at atmospheric pressure 35,108,113 or under vacuum 112,115 prior to drying. Encapsulated probiotics were reported to survive better than their free counterparts during drying and during passage through the gastrointestinal tract 114 .…”