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ARS Home » Southeast Area » Raleigh, North Carolina » Market Quality and Handling Research » Research » Publications at this Location » Publication #71198


item Sanders, Timothy

Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Quality of roasted-in-the-shell or ballpark type peanuts is often quite variable and is obvious to consumers because the peanuts are eaten one or two at a time. This research was conducted to determine some of the factors related to this quality variability. Peanuts were harvested on consecutive days to determine the changes in maturity distribution as well as changes in pod sizes and seed sizes. The data indicated that pod size changed little over the harvest times but the percentage of mature pods increased about 15 percent. In the two-year study, the larger in-shell grade size (Jumbo) contained higher percentages of mature peanuts than the smaller size (Fancy) which contained 26 to 49% immature pods. Seed from these immature pods had low roast flavor and short shelf-life which results in increased potential for off-flavor. This information is important to farmers in deciding the proper time to harvest to obtain maximum maturity and it is important to in-shell processors in their efforts to improve shelf-life quality of their products.

Technical Abstract: In-shell peanut sales provide a consistent market for virginia-type peanuts. In this market, maintenance of a high quality product which includes fresh roasted peanut flavor, is a recurring challenge. A maturity-seed size-quality relationship has been established for shelled peanuts. To determine if this relationship is true of in-shell peanuts, relationships of maturity, pod size and seed size were investigated. In two crop yr for 4 to 5 consecutive d, virginia-type peanuts (NC 9) were harvested and sorted into the five hull scrape maturity classes. After pods were dried, they were screened to obtain the pod size distribution. Sized pods were hand-shelled and the seed were screened to obtain the seed size distribution from each pod size from each maturity class. Hull scrape pod maturity profiles revealed a decrease of ca. 14% in yellow/ orange A and an increase of ca. 14% in brown/black over the 4-5 d harvest period. Overall, pod size distribution did not change over time although slight differences were noted between yr. Pod size distribution within individual maturity classes were more variable. Data indicated that the Jumbo in-shell grade contained higher percentages of brown and black maturity classes than the Fancy grade. Fancy grades contained 26 to 49% immature pods (yellow and orange A). The seed from these immature pods, which are generally consumed individually, had low roast flavor and short shelf-life which results in increased potential for off-flavor.