Effect of Frozen Storage on the Quality of Frozen Foods—A Review

This paper reviews the quality changes that occur towards the food products during the frozen storage period.This research aims to determine the significant physical and chemical changes that had occurred onto the frozen foods.Indeed,refrigerated storage is the easiest way to preserve food within short handling time.Based on the observation,it was discovered that the kinetics reactions help to establish computer-aided quality,prediction models.In certain food products,the negative impact of temperature indicated the need for a thorough evaluation of the quality parameters of individual’s kinetics reaction.In general,a reasonable temperature to store food is-18°C for most frozen foods,and this will retain the quality of commercial storage.

Microbial profile of some ready-to-cook frozen food items sold in Dhaka city,Bangladesh

This study aimed to assess the microbiological quality of 159 animal-and plant-based ready-to-cook(RTC)frozen food items currently popular in Dhaka.Microbiological analyses were carried out to enumerate total aerobic counts of mesophilic bacteria,yeast and mold and to detect some common foodborne pathogens according to standard microbiological criteria.Higher microbial loads in all animal-based food types,other than chicken strips were found.In contrast,plant-based items were relatively safe except paratha,dal-puri,rooti chapati,and aloo-puri.Several common pathogenic bacterial species were screened by analyzing their morphological,cultural,and biochemical characteristics.Escherichia coli was prevalent in most samples,while Salmonella species were least reported.A considerable number of samples exhibited enough microbial loads at infection or intoxication levels.

Cold-chain transportation in the frozen food industry may have caused a recurrence of COVID-19 cases in destination:Successful isolation of SARS-CoV-2 virus from the imported frozen cod package surface

Coronavirus disease 2019(COVID-19)pandemic has spread in 220 countries/regions towreak havoc to human beings around theworld.At present,the second wave of COVID-19 has begun in many European countries.The complete control of COVID-19 is very urgent.Although China quickly brought the virus under control,there have been eight sporadic outbreaks in China since then.Both in Xinfadi of Beijing and Dalian outbreak of COVID-19,environmental swab samples related to imported cold chain food were tested nucleic acid positive for SARS-CoV-2.In this outbreak in Qingdao,we directly isolated SARS-CoV-2 from the cod outer package's surface swab samples.This is the first time worldwide,SARS-CoV-2 were isolated from the imported frozen cod outer package's surface,which showed that imported frozen food industry could import SARS-CoV-2 virus.

Modeling of Thermal Properties of Thermal Insulation Layered with Transparent,Opaque and Reflective Film

The popular and effective food preservation technology based on refrigeration is not sufficient for high-quality products while undergoing logistic operations(transport and retail). One of the basic factors that affects the quality of chilled and frozen food products during storage and transport is packaging. A protective function of packaging strongly depends on the material used and its composition. There are different kinds of thermal insulation used for food packaging. One of them, proposed by the authors is a multilayer structure of insulation made of rectangular air cells. The insulation can be prepared by means of plastic film featuring various properties. The paper presents how to improve an effective material designed for food freezing and transport aiming to enhance its thermal resistance through the application of different transparency, reflectivity and emissivity of the film. Mathematical model based on heat exchange equations, including conduction, convection and radiation throughout a number of parallel internal sheets of film of multilayer structures was proposed. Thermal properties depending on different transparency, reflectivity and emissivity of the film were analyzed. The model was verified experimentally showing its compatibility and obtaining a significant influence of thermal resistance according to the type of film used to make air structures, the number and thickness of its layers as well as the gaps between internal folds. For multi-layer insulation designed for the insulation of packed frozen food in the shape of a rectangle, it was recommended to apply film transmittance as small as possible for the internal parts of the structure.