Increasing the Oxidative Stability of the Wafer Lipid Fraction with Fruit Extract during Storage

Abstract

Confectionary products are increasingly popular among consumers. However, since they usually have a long shelf life (about 12 months), their oxidative stability during long-term storage becomes a significant issue. Thus, the aim of this study was to investigate the effect of addition of commercially available fruit extract on the oxidative stability of lipid fraction, extracted from wafers sheets stored 13 months at 18 °C. For this purpose, the oxidation induction times (OIT) were determined by using isothermal differential scanning calorimetry (DSC). Conjugated diene content (CD) and 2,2-diphenyl-1-pikrylhydrazyl (DPPH) antioxidant activity were also monitored. All results obtained showed that the fruit extract addition slowed down effectively the peroxidation process of lipid fraction of wafer sheets. The rate of OIT and CD changes during the first six months of storage were about two times lower for the sample with the extract (LWE) than for the control (LWS). The DPPH antioxidant activity of LWE was higher than for the LWS sample until the 8th month of storage. It was stated that fruit extract effectively enhanced the oxidative stability of lipid fraction of wafers up until the 10th month of storage. After this period, CD values increased significantly for LWS and LWE samples, while at the same time there were no significant differences in OIT and DPPH values between both samples (p > 0.05).

Keywords

• lipids peroxidation
• oxidation induction time OIT
• differential scanning calorimetry DSC
• DPPH
• conjugated dienes