Gas Chromatographic Profile of Good Quality Raw Peanuts

Abstract

Raw Virginia peanuts were evaluated from volatiles obtained by a modified direct gas chromatographic procedure. The volatiles were eluted and absorbed onto a Tenax-MPE column which was at ambient temperatures. After the peanut sample was removed, the column was temperature programmed for the analysis. The combined peak areas of methanol, acetaldehyde, ethanol, and the acetone group (pentane, 2-propano1, propanal, and acetone) usually comprised about 80% of the total volatile peak area. Sensory data and their correlation with volatile profiles are reported.Several procedures have been used to obtain volatiles from peanuts in an attempt to evaluate peanut quality (1-5). Pattee and co-workers (3) used a procedure in which raw peanuts were slurried with water in a blender and the volatiles (present or produced) were separated, and analyzed the head space gases by gas chromatography (GC). They found that methanol, acetaldehyde, ethanol, pentane, acetone, pentanal, and hexanal constituted most of the volatiles. In most cases pentane was the largest component. They indicated that both pentane and hexanal appear to be related to lipoxidase activity.Brown and co-workers (5) used a procedure in which the raw peanuts were ground for one min in a blender; 740 mg of this sample was stripped at 130 with the carrier gas (N2) onto the top of the cold (about 30 C) GC column for 23 minutes. After the sample was removed, the GC column was temperature programmed to 190 C to determine the volatiles. Very little pentane was found, but a few major and minor components were found in the volatile profile. This procedure has the advantage of determining the volatile profile directly from the ground sample and it also minimizes artifacts caused from solvent extraction or chemical modifications except for those that may occur by heating in the inlet. The procedure requires 'Research Chemist, Food Technologist, and Research Chemist, respectively,

A Method for the Rapid Analysis of Headspace Volatiles of Raw and Roasted Peanuts

“…Other investigators who have identified the same compounds are cited in Table 1. Methyl formate, 2-propanol and propanal have been reported by previous workers Lovegren et al, 1982;Ho et al, 1982, respectively) but were not identified in this work.…”

Chemical, Physical and Sensory Characteristics of Peanut Milk as Affected by Processing Conditions

“…Reduction of green, beany flavor in soybean milk has been partially accomplished by hot water extraction (Wilkens et al, 1967) and treatment with proteolytic enzymes (Fujimaki et al, 1971), aldehyde dehydrogenase (Chiba et al, 1979) and aldehyde oxidase (Takahashi et al, 1979) raw peanuts and peanut milk are similar to those present in soybeans and soybean milk. These include methanol, acetaldehyde, ethanol, pentane, acetone, pentanal and hexanal (Pattee et al, 1969;Lovegren et al, 1982). Bourne et al (1976) reported that there was a traditional belief among consumers that the use of a mild alkali such as NaHCOS improves eating quality of cooked common dIy beans.…”

Comparison of Sensory Properties and Headspace Volatiles of a Peanut Beverage Processed at Different Temperature and Time Conditions

“…Volatile components of raw peanuts have been attributed to the action of lipoxygenase (Brown et al, 1977;Pattee et al, 1969 , 1976). Methanol, acetaldehyde, ethanol, pentane, acetone, pentanal and hexanal constituted most of the volatiles in published reports (Pattee et al, 1969;Lovegren et al, 1982).…”