Document V3RVpkQbJ3X9kG3NXdzEJw6kK

526 CHAPTER 48 Transit from California (U. 8. Dept of Agriculture Bulletin 505, 1936,0.86). G. W. Mann, EL A. Gorman, Jr., nod W. V. Hukill: Stage Icing in the Refrigeration of Orange* in Transit from California (U. 8. Department of Agriculture Bulletin 857, September 1943). ' W. F. Newhall and W. Grierson: A tow cost self-polislimg fungi cidal water wax for citrus fruit (Citrus Magazine, March 1956). & V. Philips aod W. Grierson: Cost advantages of bulk handling citrus through the packing house {Proceedings, Florida State Horticultural Society, VoL 70, (m press) 1957) D. 8. Prosaer, Jr., et al: Bulk Handling of Fresh Citrus Fruit (Florida Experiment Station Technical Bulletin No. 564, 1955). 1962 Guide And Data Book D. H. Rose, H. T. Cook, and W. EL Redit: Harvesting, Handli. and Transportation of Cunts Prods (O. S. Department of culture Bibliographical Bulletin No. 13, January 1951). ^ri* D. H. Rose, T. M. Whiteman, and R. C. Wright: Siam** -t Fruits, Vegetables and Florists Stocks (U* 8. Agriculture Circular 278, 1933 (now superseded by Hnrihoo][ Storage of Florida Oranges (TJSDA HTAS Office Report N<* 219, 1949.) ^a __J. S. Wiant, et al: Storage Tests on Florida Oranaes (TISHa HTAS Office Report No. 236, 1951). A CHAPTER 49 STORAGE OF EGGS AND EGG PRODUCTS Eggs: Quality Factors, Commercial Grading, Keeping Quality, Control of Quality in Storage; Egg Products; Quality Factors, Processing, Freezing and Dehydration, Storage life. Defrosting; Refrigeration Design Doha HE annual production of eggs in the United States now given to this point so as to produce a uniform, and generally, Truns close to three billion dozens. A substantial propor a light, yolk color. tion of these are produced during the spring months, particu- The nutritive value of eggs is high; they class as one of our Jariy is the Midwest where farm flocks prevail. This produc protective foods, being especially valued for their high quality tion pattern gives rise to a surplus of eggs in the Spring. The protein and vitamin content. Nutritive value is very much surplus is mostly stored as shell eggs, although increasing affected by the feed of the hen, but hardly affected by handling quantities are being first processed and then stored as frozen or storage. and dried eggs. COMMERCIAL GRADING SHELL EGGS Commercially, egg quality is determined by candling. This The bulk of the shell eggs moves into storage during Febru shows the interior quality and whether the egg meets the ary, March and April, and out of storage during August, specifications of the U. S. Standards for Quality of Individual September, October and November. Shell Eggs with respect to albumen and yolk quality. Many The long term storage of eggs is gradually decreasing as the states use the same or similar standards; some are obligatory; production of eggs becomes more steady the year around. As others axe permissive. Weight classifications are also com this trend grows there will be more short term and less long monly used. These are usually divided into the following cate term storage practiced. Thus, the warehousing of eggs is be gories: jumbo, 30 oz per doz; extra large, 27 oz per doz; large, coming a matter of backlogging stocks for handling and grad 24 os per doz; medium, 21 os per doz; small, 18 oz per doz; and ing, and for adjusting supply to the current demand. The peewee, 15 os per doz. problems of handling eggs in warehouses are somewhat dif In the past, eggs were rand^d and graded by hand. In ferent today than a decade ago. It is in the latter setting that creasingly, however, these operations are being mechanized, tbe handling of shell eggs in cold storage will be discussed. particularly handling and weighing. QUALITY FACTORS KEEPING QUALITY The following criteria are usually used in evaluating egg quality: 1. Appearance 2. Odor and flavor 3. Nutritive value 4. Culinary value 5. Microbiological condition Most consumers think of fresh-egg quality in terms of ap pearance, odor, and flavor. An egg having a thick, gelatinous white completely surrounding an upstanding yolk is desired. The odor and taste should be normal (mild and eggy); there should be no defects present (cracks, dirt, blood spots, green whites, etc.). Generally eggs used for frying and poaching must meet the most exacting standards; those for cooking the least. All fresh eggs are not of high quality. Most people are familiar with the fact that newly-laid eggs may have weak, cracked, or misshapen shells. These conditions arise due to poor genetic background of bens, faulty management, hen nutrition or even disease. It is not so well known that fresh eggs can and do occasionally contain foreign objects, particularly bbod and meat spots. In addition, they may possess weak and watery whites and mottled yolks. These latter conditions are affected by the breeding behind the hen, her age, aod disease history. Respiratory disorders are particularly damaging to egg quality. The color of the shell is purely a matter of breeding. There is no difference in quality between brown and white eggs. Yolk color is entirely a question of the kind and amount of color in the feed of the hen. In commercial flocks close attention is The use of refrigeration ranks highest of all controls which may be applied in the preservation of quality in shell eggs..' Literally hundreds of methods for treating eggs have been devised for extending their edible life; none has surpassed the effectiveness of low temperatures. Clean, sound eggs, properly packed, promptly cooled and kept at 29 to 31 F retain their quality remarkably well for several months. Recently the use of mechanical refrigeration in the cooling and holding of eggs on the farm has become more common. It is predicted that this practice will increase rapidly in com mercial egg production areas. The recommended conditions are 50 to 60 F and 70 to 80 percent rh. -Eggs handled under these conditions effectively prevent quality loss on tire farm and still avoid the sweating problem when the eggs are re moved and transported to the candling and grading plant. Qualitatively there are three distinct kinds of deterioration in shell eggs: (1) changes brought about by chemical reac tions, (2) decomposition by bacteria and molds, and (3) changes in flavor and odor brought about by absorption of foreign substances. Some of the changes taking place during storage are brought about by chemical action and the effect of temperature. Cool temperatures have a beneficial effect on quality. If eggs are fertile, other and more serious changes will take place at temperatures above 68 F. Commercially produced market eggs are usually infertile, so this problem is not a serious mat ter. Unfortunately, many farm flock eggs are fertile and these can, and do, undergo serious changes. The more obvious' effects are a flattening of the white and yolk which makes the eggs unsuitable for frying or poaching if it progresses far 57 t ?! ,, 3 i "I -k