Hot air drying and freeze drying pre-treatments coupled to explosion puffing drying in terms of quality attributes of mango, pitaya, and papaya fruit chips

Abstract

To further improve the quality of traditional combined hot air and explosion puffing drying (AD‐EPD) dehydrated tropical fruit, freeze drying, as a pre‐drying treatment, combined with explosion puffing drying (FD‐EPD) was applied to dry mango, pitaya, and papaya fruit. Comparative study of AD‐EPD and FD‐EPD in terms of physicochemical, texture, color, microstructure, and rehydration properties of the three tropical fruit chips was done. Compared with AD‐EPD, the crispness and the volume ration of the three tropical fruits were significantly improved when EPD coupled with FD. The lowest color difference, as well as high retention of physicochemical characteristics was found in FD‐EPD prepared chips. The improvements of texture and color in FD‐EPD dried fruit chips were confirmed using a 15‐member sensory evaluation. In terms of integrated quality of the three tropical fruit chips, FD‐EPD could be further applied to process valuable materials. Practical applications Drying has been applied to extend the shelf‐life of seasonable fruit. With the development of drying industry, more and more advanced drying technologies are required. Explosion puffing drying (EPD) is a novel drying technology, which has many advantages, such as improving product's quality, increasing the drying rate and reducing the cost. Freeze drying (FD), as one of the innovative drying methods can be applied to combine with EPD (FD‐EPD) to dry tropical fruit (mango, pitaya, and papaya). The tropical fruit chips dried by FD‐EPD are presented integrated quality. Overall, FD‐EPD will be a promising drying technology for preparing tropical fruit chips.

Apple juice concentrate impregnation enhances nutritional and textural attributes of the instant controlled pressure drop (DIC)‐dried carrot chips

“…This is in consistent with the results of the study by Xiao et al ., who found that the DIC‐dried apple chips osmotically treated with different types of mono‐, di‐, and tri‐saccharide showed a similar hardness when SG was controlled at the same level. Crispness is an indicator of chewing, which is greatly related to the microstructure of crispy fruit and vegetable products . As expected, all of the osmotic pretreated samples exhibited higher crispness values (> 1.97 mm) than the un‐pretreated carrot chips (0.87 mm).…”

“…Crispness is an indicator of chewing, which is greatly related to the microstructure of crispy fruit and vegetable products. 31 As expected, all of the osmotic pretreated samples exhibited higher crispness values (> 1.97 mm) than the un-pretreated carrot chips (0.87 mm). All of the above results indicate that apple juice concentrate can be used as an osmotic solution to improve the textural properties, which plays the same role as sucrose and maltitol.…”

High pressure‐assisted vacuum‐freeze drying: A novel, efficient way to accelerate moisture migration in shrimp processing

“…At present, solar drying is gradually replaced by hot‐air drying, which is widely used in food production because of its short drying time, simplified operation, controllable conditions, easy implementation, low investment cost, and more hygienic characteristics than those of solar drying (Maurya, Gothandam, Ranjan, Shakya, & Pareek, ; Ren, Perussello, Zhang, Kerry, & Tiwari, ). However, there are several disadvantages and limitations of these thermal drying techniques, which often cause heat damage and affect the color, flavor, texture, and nutritional value of the product, resulting in degradation of the final dried product quality (Valadez‐Carmona et al., 2017; Yi, Lyu, Bi, Zhou, & Zhou, ). To overcome this problem, there is an urgent need to introduce superior and more sophisticated preservation techniques to obtain dehydrated foods with high quality.…”

Effect of the moisture equilibrium process on the expansion behavior of instant controlled pressure drop (DIC) drying of dried apple cubes

“…For heat sensitive materials, it is desirable to process them under mild conditions, so vacuum freeze drying is preferred in recent years, because it can maintain a good shape of the final products. However, the energy consumption of vacuum freeze drying is high, and freeze‐dried food products have the characteristics of highly hygroscopic and lack in flavor, which limits the application of this drying technology in industrial production . In contrast, the hybrid drying process has advantages in terms of low energy consumption, high product quality and high drying efficiency compared to the conventional drying processes.…”

“…At present, many studies have shown that DIC can change the texture properties of products and improve the quality of product. This drying technology has been successfully applied in processing of various fruit or vegetable materials such as apple, peach, mango, papaya, strawberry, jujube, and carrot . Most studies have focused on improving the quality of DIC dried products, including the adjustment of the operating parameters (such as puffing temperature, number of decompression, continuous vacuum time, and continuous vacuum temperature, etc.)…”