Effects of temperature and packaging materials on oxidative and sensory stability of raw peanuts during storage

MARTIN MARIA PAULA; QUIROGA PATRICIA RAQUEL; RIVEROS CECILIA; GAYOL M. FERNANDA; LARRAURI MARIANA; GROSSO NELSON R.; NEPOTE VALERIA

Córdoba

Congreso; VI Congreso Internacional de Ciencia y Tecnología de los Alimentos; 2016

Secretaría de Ciencia y Tecnología

Oxygen and temperature are important factors affecting peanuts lipid oxidation. Previous studies demonstrated that high barrier plastic bags under vacuum (EVOH) provide raw peanuts with a higher protective effect against chemical and sensory deterioration in comparison to polypropylene ventilated materials (PP) during storage at 40 °C. The present research is a continuation of the mentioned study and attempts to simulated storage conditions when peanuts are stored for a longperiod. The aim was to investigate the effects of different temperatures on chemical and sensory quality of raw peanuts packed in two different packaging materials during 540 storage days.Raw peanuts samples were packaged in EVOH bags under vacuum and PP bags and were stored at 25 °C (T25) and 10 °C (T10) during 540 days. Peroxide value (PV), conjugated dienes (CD) and fatty acid composition (by GC) were evaluated every 60 days. Sensory descriptive analysis was alsoperformed on peanuts samples. Three-way variance analysis (factors: treatment, time, and temperature) and LSD Fisher´s multiple range test were used for statistical analysis.Significant differences ( = 0.05) were found for the interaction treatment*time*temperature for PV and CD which increased with storage time. In EVOH-T10, PV (from 0.63 to 1.28 meqO2 Kg-1)and CD (from 1.14 to 1.41 1%, 1cm) were very stable during storage. The results from EVOH-T10were significant lower in comparison with other samples. The main significant differences in the fatty acid composition were observed in saturated/unsaturated ratio (S/U) for both packaging and storage temperature. PP-T25 exhibited the highest S/U increase (from 0.15 to 0.17) during 540 storage days due to higher linoleic acid losses for oxidative deterioration in this peanut sample.Sensory analysis showed that roasted peanutty flavor decreased with storage time.Significant differences were observed for the interaction treatment*time*temperature. At storage day 540, the highest intensity ratings were detected for EVOH-T10.The results indicate that raw peanuts packaged in EVOH under vacuum effectively protect the product against oxidation and sensory deterioration in comparison to raw peanuts packaged in PP under normal atmosphere. In addition, storage temperature is an important factor that affect raw peanut quality.