Changes in the volatile profile of peanuts and their relation to enzyme activity levels during maturation

Abstract

The profiles of volatiles from uncured peanut kernels, sampled weekly from the 6th to the 13th after pegging, were determined using gas-liquid chromatography and mass spectrometry. Total volatile production of the kernels reached a maximum at 8 weeks, decreased rapidly to a near minimum value at 11 weeks, and showed a slight increase a t 12 weeks. Observations beyond 12 weeks indicate that total production of volatiles gradually decreases. Five major volatile components were identified:acetaldehyde, methanol, pentane, ethanol, and hexanal. Traces of acetone and pentanal also were detected. Except for hexanal, which first appeared at 8 weeks, all major components were present throughout maturation. Possible relationships between alcohol dehydrogenase and lipoxidase activities and the fluctuations in acetaldehyde, ethanol, pentane, and hexanal during maturation are discussed.he volatile profiles of mature fruits (Creveling et al., 1968; Sevenants and Jennings, 1966; Jennings et a/.,

A Visual Method of Determining Maturity of Shelled Peanuts1

“…Studies by Pattee et al (1970Pattee et al ( ,1974 with cv. NC 2 noted that immature kernels tend to be torpedo-shaped, with the testa color varying from pink (embryonic end) to white.…”

“…2). This Immature class would encompass up to stage seven of the kernel maturity classification system developed by Pattee et al (1970Pattee et al ( , 1974. As the pod and seed development proceeded, kernels tended to become more rounded, and testa color moved from white towards its mature color [which in studies by Pattee et aE.…”

“…In the case of Florunner, as with NC 2 andVirginia Bunch 67, as the seed matured the testa darkened, changing to darker pink and then towards brown (Pattee et al, 1970(Pattee et al, , 1974Schenk, 1961). The shape of the mature seed were similar to those we classed as Mid-mature (W = 1.43, Table 2).…”

“…When kernels showed evidence of the waffle like imprint of the hull and brown blotching we classified them as "Mature". The Mature class would encompass stages 11 through 15 of the kernel maturity classification system of Pattee et al (1970Pattee et al ( , 1974.…”

Evidence for an Elongation/Reduction/C1-Elimination Pathway in the Biosynthesis of n-Heptane in Xylem of Jeffrey Pine

“…The long-chain acyl COA is then reduced to an aldehyde and free COA, and the former undergoes either decarbonylation to form a hydrocarbon and carbon monoxide Kolattukudy, 1984, 1988;Kolattukudy, 1991, 1992;Yoder et al, 1992) or decarboxylation to form a hydrocarbon and carbon dioxide, as has been recently demonstrated for hydrocarbon biosynthesis in insects (Reed et al, 1994(Reed et al, , 1995Mpuru et al, 1996). n-Pentane found in developing peanuts also appears to arise from an acyl lipid, albeit directly from the lipoxygenase-catalyzed degradation of linoleic acid without the involvement of an aldehyde intermediate (Pattee et al, 1970(Pattee et al, , 1974Garssen et al, 1971;Johns et al, 1973). In an early study of short-chain alkane biosynthesis in P. jeffieyi (Sandermann et al, 1960), the labeling pattern of n-[74C]heptane generated by incubating tissue slices with [2-I4C]acetate was consistent with chain elongation via a fatty acid synthase-type polymerization of acetate units.…”