Assessment of convection, hot‐air combined with microwave‐vacuum and freeze‐drying methods for mushrooms with regard to product quality

Abstract

Combined drying of hot air and microwave-vacuum has been proposed as an alternative method to improve the quality of dried mushrooms, especially the structural and textural properties. In the present study, the effect of different drying methods namely, convective hot-air drying, hot air combined with microwavevacuum drying and freeze-drying on qualitative attributes of pretreated mushrooms was investigated. The quality assessment was based on colour, texture, density, porosity and rehydration characteristics of the dried mushrooms. Combined drying of hot air and microwave-vacuum resulted in a dried product of superior quality when compared to the slices dried completely by conventional hot air, exhibiting lower overall colour variation, higher porosity, greater rehydration ratio and softer texture. In a dry state, mushrooms with a puffy structure and unique crispy texture were created by the combined drying method, which might be considered as important characteristics for developing nonfat snack-type food products.

Moisture sorption isotherms and isosteric heat of sorption of leaves and stems of lemon balm (Melissa officinalis L.) established by dynamic vapor sorption

“…Prior to experiments, the leaves were picked manually from the stems. The samples were dried in a high precision hot-air laboratory dryer (Argyropoulos, Heindl, & Müller, 2011) at a temperature of 40 C, maintaining 10 g/kg of specific humidity and an air velocity of 0.2 m/s until constant mass was achieved. The dried leaves and stems were kept packed in aluminum coated polyethylene bags and stored at ambient conditions in the laboratory before the determination of moisture sorption isotherms.…”

Analysis of the volatilome of Calocybe gambosa

“…This is of special interest for the food industry. Fungal fruiting bodies are typically dried in convection dryers (Argyropoulos et al 2011), and dried mushrooms such as Boletus edulis have an appreciable market value (Aprea et al 2015). However, the drying process may negatively impact the mushroom flavor, and commercially available dried fruiting bodies may be of minor quality due to changes in the aroma composition.…”

Sorption behaviour of papayas as affected by compositional and structural alterations from osmotic pretreatment and drying

“…A detailed description of the experimental system has been given by Argyropoulos et al (2011aArgyropoulos et al ( , 2011b. The drying experiments were carried out at a temperature of 70°C, constant specific humidity of 10 g kg À1 dry air and air velocity of 0.5 m s À1 until constant mass of the samples was achieved corresponding to a moisture content of 13.5 ± 0.05% wet basis (w.b.)…”