Monitoring of Weight Losses in Meat Products during Freezing and Frozen Storage (original) (raw)
Related papers
Structural Studies on Unpackaged Foods during Their Freezing and Storage
Journal of Food Science, 2006
During the freezing and frozen storage of unpackaged foods, their surface is exposed to mass transfer with the environment. Basically, ice sublimes and forms a dry, porous layer. This fact alters the sensory characteristics of the products and originates an important quality loss. In this work, a mathematical model was used to predict the thickness of the dehydrated layer, taking into account the influence of operating conditions and food characteristics. Based on the predictions of the numerical model, 2 regression equations were proposed to calculate the size of the dehydrated layer after freezing and storage, having the operating conditions and food properties as parameters. Besides, the frozen storage of the products was studied over different time periods (1, 2, and 3 mo) using beef cylinders and slices, as well as minced beef balls and hamburgers. The dimension of the dehydrated layer and the induced changes in the food surface structure were determined by image analysis and environmental scanning electron microscopy (ESEM). The experiments determined an increase in the depth of the dehydrated layer when storage times are longer, which could be adequately related to storage conditions through the predictions from the numerical model and the regression equations.
Weight loss during freezing and storage of unpackaged foods
Journal of Food …, 2001
Dehydration of unwrapped foods occurs during freezing and frozen storage. Coupled heat and mass balances were proposed incorporating solidi®cation of water and sublimation of ice. The mathematical model was solved using an implicit ®nite-dierences method, with a variable grid to follow the moving sublimation front. The model evaluates temperature and water concentration pro®les and was used to predict the kinetics of weight loss for dierent products. Model predictions were favourably compared against experimental data on weight loss during storage of unwrapped meat, potato and tylose.
Freezing rate effects on the drip loss of frozen beef
Meat Science, 1980
One of the quality parameters of frozen meat is the amount of exudate which arises during thawing. The amount of drip obtained by centrifugation under standard conditions, and the protein composition of the exudate, has been correlated for different thermal histories.
The prediction of freezing meat inside the cold storage is studied experimentally and numerically using CFX14.5. In the present work a prototype cold storage for meat has been designed and constructed with dimensions 1 m in length x 1 m in width x 1 m in height. Temperature distributions of regular shape of meats were determined for storage temperature-21°C inside the cold storage, where each part of meat is located in one of the three levels (bottom, medium and top) inside the cold store. The air velocity distribution has been measured by using metal vane anemometer in the directions of (x,-x, y,-y, z and-z) around the meat and the results have been used in the numerical simulations. In the numerical simulations the temperature distributions are based on transient, Navier-Stokes equations, turbulence is taken into account using a standard model for air flow and assumed as steady turbulent state, meats are presented as solid domain with variable thermophysical properties as function of temperature and mass and heat transfer due to evaporation are regulated due to including product casings. During the freezing the properties of meat change during the three stages each stage having specific properties. The minimum temperature of the product was located in the top level and very close to their surrounding storage air temperature both due to exposure to higher air velocity from the fans. The total error of compression between the experimental and numerical temperature distributions of meats is equal to 18.7%.
International Journal of Refrigeration, 1994
Freezing times of beef meat balls were experimentally determined in a prototype belt freezer. Working conditions covered a wide range of velocities and temperatures of the refrigerating air. The air flowed parallel or through the belt, either upwards or downwards, thus resembling the way in which different industrial equipment operates. Freezing times were predicted by a numerical method and by six recently developed approximate methods, using three different sets of thermal properties for minced beef. The comparison of experimental and predicted freezing times showed that both the numerical method and the values of the heat transfer coefficient were adequate. However, the results predicted by the different approximate methods depended strongly and with no definite trend on the values of thermal properties used.
Transactions of the ASAE, 1974
A LTHOUGH the freezing of food has become an accepted preservation process for many food commodities, the design of the equipment utilized for freezing is usually based on experimental data which may or may not correspond to the design conditions. In addition, very few attempts have been made to design the freezing process to assure optimum product quality. Most freezing design computations lead to determination of refrigeration requirements and/ or freezing rate for the product. Although the refrigeration requirement for freezing depends only on the final temperature of the frozen product, the rate of freezing may have a significant influence on product quality. Probably the most basic characteristic of a frozen food needed in freezing design computations is the relationship between the frozen water fraction and temperature. Accurate knowledge of this relationship allows calculation of all factors required in the design of the system for freezing of food. Experimental approaches to design normally involve measurement of total heat content of the product at various temperatures in the freezing temperature range. There are several inherent limitations to these measurements including experimental errors and the inability of the experimental conditions to simulate all design conditions. The objectives of the investigation were: 1 To develop an approach which will allow prediction of the unfrozen water fraction as a function of tempera
Effect of Thawing on Frozen Meat Quality: A comprehensive Review
Meat and meat products provide essential nutrients such as protein, fat, vitamins and minerals by making an important role in dietary intake. The overall eating quality of meat and meat products is affected by characteristics like taste, texture, juiciness, appearance and odor. Texture is deemed to be most important characteristic of all. Nowadays in busy life meat in bulk quantity is purchased for further usage that required thawing i.e. a loss of nutrition as well. The quality of frozen foods is main concern in many cases due to less attention is paid towards thawing process. However, thawing is significant cause of quality damage in freezing process due to many reasons. Proper precautionary measures must be practiced during meat thawing process to avoid microbial spoilage, which includes temperature below danger zone and reduced thawing time.