Composition of raw and roasted runner, Spanish and Valencia market type peanuts

Abstract

Spanish, Valencia, and runner are three peanut market-types which have distinct physical and chemical profiles that can affect flavor and industry uses. Market-type and roast treatment (raw/roasted) were evaluated for physical and chemical differences between raw (skin removed) and dry roasted seeds. Samples were analyzed for seed weight, moisture content, water activity, total oil, fatty acid profiles, tocopherols, protein, sugars, and free amino acids. Runner-types had the largest seed weight relative to Spanish and Valencia seeds. Roasting significantly affected moisture content and water activity. Total oil ranged from 49.66 % to 55.63 % with the runner samples having the highest content. Oleic, palmitic, and linoleic fatty acids were the most abundant in the samples and significantly differed between market-types with ranges between 54.74 % and 82.65 %, 5.82–9.04 %, and 2.63–3.06 % respectively. Samples were discriminated by market-type for alpha, beta, and gamma tocopherols. The Valencia-types were highest in protein. Sucrose was the major sugar quantified, but market-type and roasting had no effect on the content. Glucose and fructose levels significantly decreased after roasting. Several free amino acids were differentiated by market-type, but glutamic acid and phenylalanine were the most abundant in all the samples. Roasting demonstrated a significant effect on several free amino acids.