PURPOSE OF THE INVESTIGATION 



The widespread use of convenience foods has 

 created interest in the comparative quahty, jneld, 

 and time required for kitchen preparation of fresh, 

 canned, and frozen fruits and vegetables. Al- 

 though canned fruits are still most widely used 

 (-/4))^ other types of convenience foods have made 

 rapid gains. More than 704 million pounds of 

 frozen fruits, excluding citrus products, were 

 packed in 1961 {19). Information regarding the 

 quality of frozen fruits on the retail market is 

 therefore timely. 



Extensive investigations of the quality of 

 frozen fruits obtained directly from a processor 

 have been reported by the Western Utihzation Re- 

 search and Development Division of the Agricul- 

 tural Research Service (8, 9, 15) and by the 

 Wisconsin Alumni Research Foundation (S, 5). 



Relatively Uttle research has been reported, 

 however, on the quality of frozen fruit from retail 

 market channels. Kelsey has pointed out that 

 high temperature during transportation and stoi- 



2 Italic numbers in parentheses refer to Literature Cited, 

 p. 28. 



age has an adverse effect on quality of frozen food 

 in retail stores {10). Surveys conducted by 

 Morin {17), Dykstra {6), and Alunter and others 

 {18) indicated mishandling of frozen foods in retail 

 stores. Lamden and others {13) found that the 

 ascorbic acid content of chilled orange juice pur- 

 chased in the Burlington, Vt., area was consider- 

 ably lower than that of fresh orange juice. 



Research on relative costs in time and monej^ 

 involved in the purchase and use of different foods 

 in different stages of preparation has been carried 

 out by Iowa State University in cooperation with 

 the Federal Extension Service, U.S. Department 

 of Agriculture ill). 



The present study was carried out in coopera- 

 tion with the Marketing Economics Division, 

 Economic Research Service, to obtain data on 

 preparation-tijue requirements, yield in servings, 

 and product quality of a variety of foods in dif- 

 ferent market forms. Information on vegetables 

 has been reported {23). Research was conducted 

 by the Economic Research Service on companion 

 projects to determine the effects of processing for 

 consumer convenience on retail food prices. 



SCOPE OF THE WORK 



Fruits widely available in various market forms 

 on the retail market were included in the study. 



Fresh fruits investigated were dark sweet 

 cherries, red sour cherries, cranberries, grapefruit, 

 lemons, oranges, peaches, pineapple, plums, red 

 raspberries, rhubarb, and strawberries. 



Canned fruits selected for study included baked 

 apples, dark sweet cherries, red sour cherries, 

 cherry sauce, strained and whole cranberry 

 sauces, grapefruit sections, lemon juice, orange 

 juice, peach halves, pineapple chunks and slices, 

 plums, red raspberries, whole strawberries, and 

 strawberry pie filling. 



Because of the scarcity of information regarding 

 the quality of frozen fruits available to the ultimate 

 consumer, a considerable portion of the study was 

 directed to an investigation of frozen fruits. 



Six frozen fruits were selected for detailed 

 quahty evaluation because they are among those 

 packed in the largest quantity {19). These fruits 

 were grapefruit, orange juice concentrate, sliced 

 peaches, pineapple chunks, red raspberries, and 



strawberries. Four additional frozen fruits — 

 baked apples, red sour cherries, lemonade con- 

 centrate, and rhubarb — were used in a more 

 limited study. 



Preparation time and yield were determined on 

 fresh, canned, and frozen fruits. Preparation 

 time included time spent in preparation by com- 

 monly used household methods, as well as cooking 

 time for those fruits that required cooking. 



On most samples of fresh, canned, and frozen 

 fruits, quality evaluations included reflected color 

 measurements, shear-force readings, and panel 

 scores for color, texture, and flavor. 



Additional quality evaluation tests carried out 

 on five of the six frozen fruits (orange juice 

 excluded) and on the juice fractions of the frozen 

 fruits were: Reduced ascorbic acid, dehydro- 

 ascorbic acid plus diketogulonic acid, soluble 

 solids, and titratable acidity. On orange juice 

 concentrate, determinations were made of thaw- 

 ing index (TI), sensitivity index (SI), and reduced 

 and oxidized ascorbic acid. 



EXPERIMENTAL PROCEDURES 



Purchase and Storage of Fruits 



All fresh, canned, and frozen fruits were pur- 

 chased from retail markets in the Washington, 

 D.C., metropolitan area during the years 1960 

 and 1961. 



Fresh fruits were purchased the day before 

 testing, at the peak of the season for each fruit. 

 They were stored in a walk-in refrigerator at 42° F. 

 until used. 



Canned fruits were stored from one to two weeks 

 at 72° F. before use. When available, two brands 

 of each fruit were purchased. 



