Peas (Pisum sativum) are an important constituent in the diet of many people. Peas may be cooked and eaten as green peas shortly after harvest, stored for short periods in the pods, or, after suitable treatment, stored for long periods before consumption. Many factors influence the yield and quality of frozen peas but maturity requires careful consideration because of the relation of maturity to color, flavor, and texture. The objectives of this thesis were to determine the effect of the maturity stage on the quality of the frozen peas during processing and storage and to correlate the interactions between the sensory evaluation panel with the physical and chemical quality factors measured. Venus pea variety grown under commercial conditions at the Sublimity area east of Salem, Oregon, were used in this study. The trials were randomized, for three stages of maturity with three replications per each stage of maturity. Each of the three maturity stages was harvested; vined; blanched by steaming at 98.8°C (210°F) for 30 sec for the immature peas, 60 sec for the mature peas, and 90 sec for the overmature peas; frozen at -37.2°C (-35°F) for 24 hr in an air blast freezer and stored at -23.3°C (-10°F) for 4 and 8 month. During processing and. storage the following factors were determined: tenderometer value, total solids, alcohol insoluble solids, peroxidase activity, ascorbic acid., total sugars and sensory evaluation. In the sensory evaluation analysis starchiness, sweetness and tenderness intensity, as well as texture, flavor and overall desirability were measured. Analysis of variance and least significant difference were used to compare the effect of pea maturity during processing and storage on the different quality factors measured. Correlation coefficients were used to determine the relationship between these factors. Immature peas had lower tenderometer value than overmature peas. Tenderometer value of peas decreased, during processing. The highest total solids content was observed, in the overmature peas and the lowest total solids content in the immature peas. This behavior was also observed in the alcohol insoluble solids content. Raw peas in the three maturity stages had the same initial peroxidase activity and the significant effect of the maturity level found in the residual peroxidase was affected by the different blanching time applied at each maturity stage. The ascorbic acid content was significantly affected, by the maturity level and was reduced during the blanching treatment. Total soluble sugar content was higher in immature peas and lower in overmature peas. All the sensory evaluation parameters measured were affected by the maturity. In general, the taste panel found higher flavor desirability on the mature peas but when texture and overall desirability were measured immature and mature peas were equally preferred. Significant correlations were found between physical, chemical, and sensory parameters analyzed, some of them are tenderometer value and alcohol insoluble solids; total solids and alcohol insoluble solids; alcohol insoluble solids and overall desirability. / Graduation date: 1981

Call number: LD2668 .T4 1961 S77

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Graduation date: 1950