Doctoral Dissertations

Date of Award

3-1982

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Food Science and Technology

Major Professor

C. C. Melton

Committee Members

H. O. Jaynes, W. R. Backus, W. T. Butts

Abstract

Standard meat curing procedures demand refrigerated systems in addition to salt, sugar and sodium nitrite (Kramlich et al., 1973). These are not readily available in most underdeveloped countries. Meat preservation as practiced in underdeveloped countries is mainly by drying. Such products are either very hard and unacceptable for most average income consumers, or they are susceptible to mold and have a short shelf life. Papaya is easily available in most of the tropical countries and contains proteolytic enzymes used in tenderizing meat (Hay et al., 1953). This study was aimed at producing a more palatable dried meat product having good shelf life with raw materials and equipment likely available in underdeveloped countries. In each of two replications, beef cubes from Commercial grade beef carcasses were randomly allotted to 36 treatment groups consisting of varying levels of NaCl (0% to 10% in 2% increments) and papaya pulp (0% to 25% in 5% increments) in a curing brine held at 23.9°C for 48 hours. After curing, these cuts were washed and dried for 45 hours at 48.9°°C to a water activity of about 0.50 and then stored at 23.9°C in polyethylene bags for two months. After one month and at the end of two months storage, products were observed for surface mold and analyzed for volatile fatty acids, titratable acidity, pH and thiobarbituric acid as indicators of quality loss as the result of both processing and storage effects. Prod-uct microbial safety was determined by Castro-Espinoza (1982). The amount of acetic, propionic and butyric acids in the products decreased with increased salt level in the curing solution. The salt added slowed rancidity development such that only about 2% salt was needed to keep the TBA number (rancidity indicator) below 0.50. The moisture content of the product increased (p< 0.01) with increased salt levels. The added papaya lowered the pH of the initial curing solution (from 7.1 in 0% to 5.1 in 25% papaya) and the pH of the finished product. Papaya also decreased (p< 0.001) the amount of propionic acid observed in the product such that only about 5% papaya was needed to lower the value from 7.4 to 3.0 mg/100 g sample. Titratable acidity decreased with increased level of salt but increased (p<0.001) with increased level of papaya. Thus the observed value of titratable acidity depends on the interaction of the salt and papaya effects. Samples stored for two months had higher titratable acidity and lower moisture content than those stored for one month. The amount of acetic and butyric acids observed decreased (p< 0.001) with increased storage periods. Products treated with 10% salt and 10% papaya brine were chosen for consumer evaluation because it produced no putrid odors during curing, showed no surface mold during storage, had a relative low amount of volatile fatty acids and low TBA number, and it was found to have acceptable microflora.

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