EFFECT OF FREEZING RATE ON MEAT.¹

Abstract

Xany conflicting statements have been published relative to the effect of rate of freezing on the quality of many frozen products. Recently, one of the authors (F.A.L.), in collaboration with others, Lee and Gortner (1949), Lee, Gortner, and Whiteombe (1949a), and Lee, Gortner, and Whiteombe (1946, described the effect of freezing rate on peas, snap beans, asparagus, lima beans, corn, spinach, strawberries, raspberries, and peaches. N o significant differences were observed that could be attributed to rate of freezing, except in the case of asparagus. This vegetable showed texture differences, but the differences were really significant only when extremes in the rate of freezing (that is. freezing in liquid air versus freezing in an insulated box) were contrasted.DuBois, Tressler, and Fenton (1940) concluded ". . . the more rapidly meat was frozen, the better was its all-around quality. However, the palatability of the roast which was frozen at the slowest rate was good; wheii cooked it was tender and juicy and of good flavor. " ( 1930, 1931) stated that phpico-chemical changes occurring in the frozen condition, rather than puncturing of cell walls by ice crystals, o r rupture of cells by expansion during freezing, was the basic explanation of the drip from thawed fish and meat. He added, after speaking about corrective treatment and drip : " l f these findings stand confirmed, the advantages of rapid freezing diminish somewhat in importance. " However, he noted that as the speed of freezing is diminished, the appearance of the resulting product undergoes a change. The same author noted (about meat) : ". . . at very slow speeds there is a marked translucence." Taylor

Storage Effects on Beef, Effect of Three Years of Freezer Storage on the Thiamine, Riboflavin, and Niacin Content of Ripened and Unripened Beef

“…Results of tests for the stability of riboflavin were less consistent. Reported changes ranged from a decrease of 31% (7) to an increase of 22 to 42% (13) in pork loins, and decreases up to 46% were reported for beef rib steaks (5). Kotschevar (4) obtained greater losses of thiamine and riboflavin in sliced calf liver than in ground calf liver stored in an atmosphere of carbon dioxide, suggesting that oxidation during freezer storage could be a factor in losses of these two vitamins.…”

The effect of processing on the nutritive value of flesh foods

“…By contrast, the rate of freezing appears to have no significant effect upon the thiamin, riboflavin, nicotinic acid, pantothenic acid or pyridoxine values in beef (Lee, Brooks, Pearson, Miller & Volz, 1950) or pork (Lee, Brooks, Pearson, Miller & Wanderstock, 1954).…”

Pigments in Vegetables

“…Carotene content showed no significant differences in snap beans, frozen at greatly different speeds, after freezing, after storage, or after cooking (Lee et al, 1946).…”