Researches on the freezing of blueberries and green bean pods using an experimental model of a fast freezing equipment

Abstract

In order to conserve perishable food and extend the permissible storage and marketing period, one of the best methods that uses artificial frost is freezing. The action of low temperatures leads to a slowing down of the modifying processes, both nutritionally and organoleptically. The researches presented within the paper aims to determine some specific parameters for the freezing process using an experimental model of a fast freezing equipment with liquid nitrogen. Experimental researches use two species of horticultural products, namely blueberries and green bean pods. The results indicate that the values of total freezing time, average linear freezing rate and liquid nitrogen consumption for quick freezing of blueberries were higher than those recorded for green bean pods. Also, with the lowering of the set temperature inside the freezing chamber, the freezing time from 0°C to the temperature of -15°C decreases, resulting in lower freezing times, higher average linear freezing rates and liquid nitrogen consumptions with increasing tendency.

Establishment and experimental verification of temperature prediction model for quick‐frozen strawberry jetted with dry ice

“…(2) Due to the short freezing time, the water evaporation had no effect on the temperature of strawberries. (Madhiyanon, Techaprasan, & Soponronnarit, 2006; Sorica et al, 2019) (3) Convective heat transfer coefficients were equal everywhere on the surface of strawberries. (4) Due to its small respiration heat and short freezing time, the effect of strawberry respiration heat was ignored (Betta, Rinaldi, Barbanti, & Massini, 2009).…”

“…Based on the research of dry ice jetting‐based quick‐freezing of strawberries, this study was conducted with the reference to different internal heat transfer models of fruits and vegetables (Huang et al, 2014; Madhiyanon, Techaprasan, & Soponronnarit, 2006; Sorica et al, 2019). On the basis of the design of the nozzle structure of the current gas particle mixture (Mat et al, 2021; Ishii, Umeda, & Kawasaki., 1987), (Xie et al, 2013) investigated the feasibility of jet cooling with R134A as the medium.…”

The effects of the novel home freezing system on microstructure, color, antioxidant activity, and microbiological properties of strawberries

“…Nowadays, consumers are more aware of the quality and the benefits of their foods than in the past, and prefer the foods that are most nutritious, healthy, closest to the fresh condition and almost no-treated ( Danesi and Bordoni, 2008 ). For this reason, even though it is one of the ancient methods, freezing technology is still unrivaled and it has become more common in the last decade and for long-term storage, in order to use the products in the off-season ( Poiana et al, 2010 ; Sorica et al, 2019 ). Deep freezing is one of the most widespread used preservation methods for foods.…”

“…( Çubukçu et al, 2019 ). Among the fruit species with the widest use for freezing can be remembered berries, strawberries, cherries, peaches and apricots ( Sorica et al, 2019 ). Zhao et al (2020) discussed the importance of freezing process that protects phenolics in berries.…”

“…If the freezing rate is sufficiently slow, the average temperature and solute/biopolymer concentration will follow closely the freezing line until the temperature of the cooling medium is reached. Large crystals resulting from slow freezing cause deformation, dislocation, and perforation of cell walls, and when defrosting these products, juice losses are high ( Sorica et al, 2019 ). Therefore providing fast freezing is important for obtaining the frozen product in better quality so the researchers aimed to try the innovative ways for quick freezing.…”