Antioxidant effects of carboxymethyl cellulose edible coatings with antioxidant on the oxidative stability of the edible pine nut

Background and objectives: Nowadays, considerable to food biodegradable and edible packaging increased. Synthetic packaging due to the problems environment Edible coating are thin layer of material which are on the surface of food products and increased the shelf life of foodstuff by providing a moisture and oxygen barrier. Edible coatings might be used as carriers of various substances, including antioxidants. Edible pine seed are susceptible to oxidation due to high levels of unsaturated fatty acids. Due to the harmful effects of synthetic antioxidants, attention to plant extracts were increased In this study the effects of CMC edible coatings containing natural and synthetic antioxidant was evaluated on oxidative stability of pine nut.
Materials and methods: carboxy methyl cellulose coating (1% W/V) with natural antioxidant valerian extract (1% W/V) and synthetic alphatocopherol (0.5 W/V) were prepared. After coating, nuts were stored for 91 days in an incubator with 35ºC and 35% relative humidity. The seeds were coated by immersion method. Moisture content, peroxide and thiobarbituric acid index were determined for samples in 7 days interval.
Results: According to the results, moisture absorption, peroxide index and thio barbituric acid index were increased in all samples with uncoated sample showing the highest moisture absorption, peroxide value, and thiobarbituric acid index . CMC coating with valerian extract delayed moisture absorption and firstly and secondary products of lipid oxidation inedible pine nut. In the end of storage time moisture content of coated sample with valerian extract (3.47) was less than uncoated (4.37) samples. These result also seen in peroxide and TBA index. The highest amount of PV (61.45) and TBA (7.1) value belonged to CMC sample.
Conclusion: Use of edible coating containing valerian extract could decrease the rate of oxidation and increased the shelf life of pine nut and can be used as a natural antioxidant with antioxidant effects for nut coatings. The best time for pine nut storage according to standard amount of PV and TBA index in different samples were 56, 63, 77 and 91 days respectively for CON, CMC, CMCA and CMCV.Conclusion: Use of edible coating containing valerian extract could decrease the rate of oxidation and increased the shelf life of pine nut and can be used as a natural antioxidant with antioxidant effects for nut coatings. The best time for pine nut storage according to standard amount of PV and TBA index in different samples were 56, 63, 77 and 91 days respectively for CON, CMC, CMCA and CMCV.