Role of thermal and non‐thermal drying techniques on drying kinetics and the physicochemical properties of shiitake mushroom

Abstract

BACKGROUND Fresh shiitake mushrooms are rich in nutrients, but have high water content, a fast metabolism after harvest, and deteriorate extremely easily. Therefore, the drying of shiitake mushrooms has become a research direction. However, the role of different drying techniques on shiitake mushroom quality is limited. Therefore, the purpose of this study was to investigate the effect of thermal and non‐thermal drying on the drying kinetics, and the physicochemical properties of the end product. RESULTS Results showed that shiitake mushroom treated with non‐thermal drying (vacuum freeze‐drying) had an attractive color, low shrinkage, and uniform honeycomb structure, while the drying time was the longest and not conducive to the formation of shiitake mushroom aroma. But shiitake mushroom treated with thermal drying presents an attractive fragrance. In thermal processing technology, compared with hot air convection drying (HAD), infrared hot air convection drying (IRHAD) shortens the drying time by 37.5%, and had the highest oxidation resistance, polysaccharide content and the lowest color change. Relative‐humidity drying (RHD) samples had the lowest shrinkage compared with other thermal processing technology. The five polysaccharides exhibited similar preliminary structural characteristics, but the polysaccharides obtained by IRHAD have the highest antioxidant properties. CONCLUSION These results showed that compared with thermal drying technology, non‐thermal drying technology is not suitable for shiitake mushroom processing. In thermal processing technology, IRHAD is a potential drying method to obtain high‐quality dried shiitake mushrooms and shiitake mushroom polysaccharide (SMP). However, it is necessary to increase the pretreatment technology to achieve the attractive appearance of non‐thermal drying technology. © 2021 Society of Chemical Industry.

Recent advances and role of melatonin in post-harvest quality preservation of shiitake (Lentinula edodes)

“…Non-thermal drying of Shiitake mushrooms preserves color and structure but lacks aroma development, while thermal drying, especially with infrared hot air convection drying, offers a quicker process, delightful fragrance, and superior qualities like reduced oxidation and high polysaccharide content. Relative humidity drying minimizes shrinkage, and polysaccharides from infrared drying exhibit the highest antioxidant properties among tested methods ( 85 ).…”

Effect of different drying methods on drying characteristics and quality of Camellia oleifera seeds

“…The moisture content of the material in the early stage of drying was higher, and the material could absorb more radiant energy during hybrid infrared-hot air drying, and the drying rate was faster. In the later stage of drying, the moisture content of the material was low, the radiation energy absorbed by the material was less, and material activation energy had also been improved, thus the drying rate decreased obviously (Luo et al, 2019;Zhang et al, 2021). Hybrid radio frequency-hot air drying could penetrate into the interior of the material and cause the oscillatory migration of polar molecules and charged ions in the material to friction with each other, so that the temperature of the material increased, and thus to achieve the purpose of drying (Liu et al, 2009).…”

The Nutrients and Volatile Compounds in Stropharia rugoso-annulata by Three Drying Treatments

“…Moreover, VFD has the advantages of maintaining the natural color, flavor, and nutrients of mushrooms. Nevertheless, it is expensive and requires specialized equipment [13]. In general, the choice of drying method depends on the specific product and the intended result.…”