Procedures to determine the appropriate classification of blanched peanuts (raw or processed) comparing with raw and roasted peanuts.

GROSSO, N.R.; ASENSIO, C.M.; QUIROGA, P.R.; LARRAURI, M.; MARTIN, M.P.; PRIETO, M.C.; LAMBIR, A. J.; GROSSO, A.; RIVEROS C.G.

2017-04-03/2017-04-27

Química

Servicios agropecuarios

INTRODUCTION. Many nuts like almonds,peanuts or hazelnuts are grown in a shell. When the shell is removed, there is still a skin on the outside of the nutmeat. Blanching is a process that removes the skins from the kernels. Blanched peanuts are prepared with raw peanuts. During the blanching process, raw peanuts go into a furnace to receive a soft heat treatment (80?100 °C) during 12 to 15 minutes. The objective of this process is to achieve that the skins realize from the kernel and can be removed easily in a subsequent stages by blanching machines. To establish whether a food product after a certain thermal and processing exposure haschanged its condition from raw to processed, physical, chemical, microbiological, andsensory parameters need to be evaluated. OBJECTIVE. The goals of this study are to compare the physic-chemical, microbiological, and sensory properties of raw, blanched and roasted peanuts in order to determine if blanched peanuts are a raw or processed food product. MATERIALS. The following samples were included in the study:  16 lots of raw peanuts provided by different peanut industries from Argentina: 4 lots from Lorenzati, Ruetsch y CIA SA; 4 lots from Aceitera General Deheza SA; 4 lotsfrom PRODEMAN SA, and 4 lots from Maniagro Argentina SA.  12 lots of blanched peanuts provided by different peanut industries from Argentina: 3 lots from Lorenzati, Ruetsch y CIA SA; 3 lots from Aceitera General Deheza SA; 3 lots from PRODEMAN SA, and 3 lots from Maniagro Argentina SA.  9 lots of roasted peanuts provided by different peanut industries from Argentina: 3 lots from Lorenzati, Ruetsch y CIA SA; 3 lots from Aceitera General Deheza SA, and 3 lots from PRODEMAN SA. METHODS. Blanching and roasting processes. Experimental design (ED): Treatments. Total = 3. The treatments are raw peanuts, blanched peanuts, and roastedpeanuts. Repetitions. 16 samples of raw peanuts, 16 samples of blanched peanuts, and 13 samples of roasted peanuts. 16 lots of raw peanuts (4 lots x 4 companies); 16 lots of blanched peanuts (3 lots x 4 companies + 4 lots produced in the lab); 13 lots of roasted peanuts (3 lots x 3 companies + 4 lots produced in the lab). Each lot is considered a repetition. Variables. Total = 15: Physical variables: color L*, a*, b* values. Total = 3 variables. Chemical variables: humidity, peroxide value, enzymatic activity (peroxidase and catalase), nitrogen solubility index, tetrazolium test. Total = 6 variables.Microbiological variables: total aerobic mesophilic plate count and total yeast and mold count. Total = 2 variables.Sensory evaluation: duo-trio discriminative test for color and flavor, descriptive test for raw and roasted flavor intensities. Total = 4 variables.