Marta G. Mestrallet

Effect of storage on chemical and sensory profiles of peanut pastes prepared with high-oleic and normal peanuts.

BACKGROUND Peanut paste and peanut butter have high oil contents and are thus susceptible to developing rancidity and off-flavours through lipid oxidation. Preservation of the chemical and sensory quality of these products is one of the main problems in the peanut industry. The purpose of this study was to compare the chemical and sensory stability of peanut paste prepared with high-oleic peanuts (cv. Granoleico, GO-P) with that of peanut paste prepared with normal peanuts (cv. Tegua, T-P) from Argentina. RESULTS Chemical (peroxide and p-anisidine values and conjugated dienes) and sensory (roasted peanutty, oxidised and cardboard flavours) indicators of lipid oxidation were measured in peanut pastes stored at 4, 23 and 40 °C. Chemical indicator values and oxidised and cardboard flavours showed lower increments in GO-P than in T-P during storage. T-P had significantly higher peroxide value than GO-P. Roasted peanutty flavour showed a lower decrease in GO-P. Peanut paste prepared with high-oleic peanuts had four (at 4 °C), two (at 23 °C) and three (at 40 °C) times longer shelf-life than peanut paste prepared with normal peanuts. CONCLUSION These results indicate that high-oleic Granoleico kernels provide peanut paste with higher protection against lipid oxidation.

Effect of peanut skin extract on chemical stability and sensory properties of salami during storage

BACKGROUND Peanut skin extracts (PSEs) have proven antioxidant properties in different food products. The objective of this study was to evaluate the effect of peanut skin extract as natural preserving compounds on chemical stability and sensory properties of salami during storage. RESULTS PSE was obtained with ethanol-water and added during the preparation of salami samples. Raw salami samples were cured and stored at 15 °C and 65% relative humidity. Moisture, peroxide value, conjugated dienes, free fatty acids and sensory descriptive attributes were evaluated on the samples. Peroxide values increased during storage in all samples and were 82.9 in control (salami without additives), 18.0 in salami with 0.2 g kg(-1) PSE (E0.02), 13.0 in salami with 1.0 g kg(-1) PSE (E0.1), and 0.63 meqO₂ kg(-1) in salami with butylated hydroxytoluene (BHT) after 42 days of storage. BHT and E0.1 treatments resulted in a lower increase in the intensity of oxidized flavor and a lower decrease in the intensity of salami flavor. CONCLUSION Chemical indicators and descriptive results indicated that PSE retards lipid oxidation and preserves sensory properties of salami, prolonging its shelf life.