Optimization of pretreatment and evaluation of quality of jackfruit (Artocarpus heterophyllus) bulb crisps developed using combination drying

Impact of pretreatment with dielectric barrier discharge plasma on the drying characteristics and bioactive compounds of jackfruit slices

BACKGROUND

Hot-air drying is a popular method for preserving the production of jackfruit, but heat treatment damages its nutritional qualities. Cold plasma is one of the pretreatment methods used to preserve quality attributes of fruits before drying. In the present work, we studied the effect of dielectric barrier discharge (DBD) plasma on the drying characteristics, microstructure, and bioactive compounds of jackfruit slices with different pretreatment times (15, 30, 45, and 60 s), followed by hot-air drying at 50, 60, and 70 °C. A homemade DBD device was operated via three neon transformers.

RESULTS

Optical emission spectrophotometry revealed the emitted spectra of the reactive species in DBD plasma, including the N2 second positive system, N2 first negative system, nitrogen ion, and hydroxyl radical. The results showed that the DBD plasma promoted moisture transfer and enhanced the drying rate, related to the changes in the surface microstructure of samples damaged by DBD plasma. The modified Overhults model was recommended for describing the drying characteristics of jackfruit slices. The contents of ascorbic acid, total phenolics, total flavonoids, total polysaccharides, and antioxidant activity in pretreated jackfruit slices were improved by 9.64%, 42.59%, 25.77%, 27.00%, and 23.13%, respectively. However, the levels of color and carotenoids were reduced.

CONCLUSION

Thus, the bioactive compounds in dried jackfruit slices can be improved using the DBD plasma technique as a potential pretreatment method for the drying process. © 2023 Society of Chemical Industry.

Insights into phytonutrient profile and postharvest quality management of jackfruit: A review

Jackfruit (Artocarpus heterophyllus Lam.), also known as 'vegetarian's meat', is an excellent source of carbohydrates, protein, fiber, vitamins, minerals, and several phytochemicals. It is a climacteric fruit that exhibits an increase in ethylene biosynthesis and respiration rate during fruit ripening. The market value of jackfruit is reduced due to the deterioration of fruit quality during storage and transportation. There is a lack of standardized harvest maturity index in jackfruit, where consequently, fruit harvested at immature or overmature stages result in poor quality ripe fruit with short storage life. Other factors responsible for its short postharvest life relate to its highly perishable nature, chilling sensitivity and susceptibility to fruit rot which result in significant qualitative and quantitative losses. Various postharvest management techniques have been adopted to extend the storage life, including cold storage, controlled atmosphere storage, modified atmosphere packaging, edible coatings, chemical treatment, and non-chemical alternatives. Diversified products have been prepared from jackfruit to mitigate such losses. This comprehensive review highlights the nutritional profile, fruit ripening physiology, pre and postharvest quality management, and value addition of jackfruit as well as the way forward to reduce postharvest losses in the supply chain.

Edible Pleurotus eryngii Papery Food Prepared by Papermaking Process

The objective of the current study was to evaluate the feasibility of papery food with Pleurotus eryngii (P. eryngii) as a raw material using the papermaking process. The physical, chemical, structural, and thermal degradation properties were studied as well as the sensory evaluation of the papery food from P. eryngii mycelia (PMP), stems (PSP), caps (PCP), and whole fruiting bodies (PEP). The results indicated that the colors from PSP, PCP, and PEP were clearly different from PMP. Thicker PSP and PMP had a smoother surface and better crispness compared to PCP. Moreover, PSP had better moisture resistance and thermal decomposition performance compared to the other groups. Nutritional composition and Fourier-transform infrared spectroscopy suggested abundant polysaccharide and protein content in all of the papery food. Finally, sensory evaluation showed that the formability, mouth feel, and overall palatability of PSP and PMP were more popular among consumers. Overall, this study provides a novel method for the preparation of papery food and provides a potential new mechanism for the further development and utilization of the fruiting bodies and mycelium of P. eryngii.

Effects of Freeze Vacuum Drying Combined with Hot Air Drying on the Sensory Quality, Active Components, Moisture Mobility, Odors, and Microstructure of Kiwifruits

In this study, freeze vacuum drying (FVD), hot air drying (AD), and FVD combined with AD (FVD-AD) were used to dry kiwifruits. Dried products were analyzed comprehensively on their sensory quality, active components, moisture mobility, odors, and microstructure. Results showed that the FVD-AD saved time by 38.22% compared with FVD while maintaining an acceptable product quality. The antioxidant properties of FVD-AD were lower than those of FVD but significantly higher than those of AD. Moreover, compared with FVD products, FVD-AD products were moderately hard (5252.71 ± 33.53 g) and improved in color, bound water, and microstructure. Additionally, FVD-AD consumed lesser drying time and energy than FD. According to cluster analysis, the odors of FVD-AD products were similar to those of the fresh ones. Principal component analysis of physicochemical and drying cost indicated that FVD-AD was a promising processing technique for functional kiwifruit snacks.

Nutritional and Health Benefits of Jackfruit (Artocarpus heterophyllus Lam.): A Review

Artocarpus heterophyllus Lam., which is commonly known as jackfruit is a tropical climacteric fruit, belonging to Moraceae family, is native to Western Ghats of India and common in Asia, Africa, and some regions in South America. It is known to be the largest edible fruit in the world. Jackfruit is rich in nutrients including carbohydrates, proteins, vitamins, minerals, and phytochemicals. Both the seeds and the flesh of jackfruit are consumed as curries and boiled forms, while the flesh in fully ripen stage can be eaten directly as a fruit. Several countries have developed different food products such as jam, jellies, marmalades, and ice creams using pureed jackfruit. The several parts of jack tree including fruits, leaves, and barks have been extensively used in traditional medicine due to its anticarcinogenic, antimicrobial, antifungal, anti-inflammatory, wound healing, and hypoglycemic effects. Despite all these benefits, unfortunately, the fruit is underutilized in commercial scale processing in regions where it is grown. The aim of this review is to disseminate the knowledge on nutritional and health benefits of jackfruit, in order to promote utilization of jackfruit for commercial scale food production.

Novel Combined Freeze-Drying and Instant Controlled Pressure Drop Drying for Restructured Carrot-Potato Chips: Optimized by Response Surface Method

Combined freeze-drying and instant controlled pressure drop process (FD-DIC) for restructured carrot-potato chips was developed and its processing conditions were optimized using response surface methodology (RSM) with the purpose of improving the quality of products and reducing energy consumption. Three critical variables including the amount of carrot, the moisture content of the partially dried product before DIC treatment, and equilibrium temperature of DIC for the restructured chips were considered. Response parameters such as the final moisture content, color value (L, a, and b), and texture properties of restructured carrot-potato chips were investigated. The results showed that the graphical optimal ranges of FD-DIC drying process were as follows: the amount of carrot was 46–54% w/w, the moisture content of the partially dried product before DIC treatment was 0.20–0.35 g/g, and the equilibrium temperature of DIC was 85–95°C. Furthermore, the numerical optimization suggested that conditions were 47.43% w/w, 0.29 g/g, and 90.57°C, respectively. It could be concluded that the combined drying method of FD-DIC provided the restructured carrot-potato chips with higher quality, as compared to the freeze-dried chips. Considering the relatively high production cost of FD, this novel FD-DIC could be an alternative method for obtaining desirable restructured fruit and vegetable chips.

Comparison of Drying and Quality Characteristics of Pear (Pyrus Communis L.) Using Mid-Infrared-Freeze Drying and Single Stage of Freeze Drying

This article provides results of an experimental investigation of hybrid- (MIR-FD), mid-infrared- (MIR) and freeze drying (FD) on the drying characteristics, energy consumption and quality parameters of pear. Rehydration ratio, color, texture, water activity, phenolic content and antioxidant activity were measured to evaluate the quality of dried pear products. Mid-infrared-freeze drying (MIR-FD) had the higher drying rate, which reduced the drying time by 14.3–42.9 % compared with FD method. Two empirical models were chosen to fit the drying curves and the models had the suitable R2 and RMSE values. Temperature characteristics of MIR and MIR-FD dried pear were determined in terms of interior temperature variation. The MIR-FD pear had darker color, better rehydration capacity, similar water activity, lower hardness (except of MIR-FD70°C) and highest content of chemical composition than single stage of FD products. Above all, the MIR50-60°C-FD was suggested as the best drying method for pear in this study.