EFFECT OF WHEY PROTEIN EDIBLE FILM PACKAGING ON THE QUALITY AND MOISTURE UPTAKE OF DRIED PEANUTS

Abstract

ABSTRACT Whey protein, a by‐product of cheese manufacture, can be used to make edible films and coatings that are oxygen, aroma, oil and/or moisture barriers. Dried peanut kernels were packed into whey protein concentrate (WPC)–olive oil composite films and stored at 25C for 4 weeks. Peroxide value (PV), moisture uptake and sensory attributes of control (unpacked) and packed samples were evaluated for 28 days. Maximum moisture uptake was found (5.40 ± 0.14%) in unpacked (control) peanut kernels, but packaging peanuts in WPC–olive oil films led to minimum moisture uptake. Dried peanut packed with WPC films with glycerol : protein ratios (w/w) of 0.7 received better crunchiness and overall acceptability than the control and other treated samples in other film compositions. WPC–oil bags reduced the PV in treated dried peanut kernels. WPC–lipid composite films can delay the development of rancidity of dried peanuts at intermediate (50%) relative humidities. Incorporation of oil in WPC films had no significant effect (P > 0.05) on the PV of packed peanuts. Weight losses of unpackaged peanuts at a higher level (10.15% w/w) were significantly bigger than peanuts packaged at a lower level (1.05% w/w). These results suggest that a whey protein‐based film is a viable alternative packaging process for peanuts and could improve the shelf life and some sensory properties of nuts. PRACTICAL APPLICATIONSWhey protein, a by‐product of cheese manufacture, can be used to make edible films and coatings that are oxygen, aroma, oil and/or moisture barriers. The mechanical properties of whey protein films can provide durability when used as coatings on food products, films separating layers of heterogeneous foods or pouches for food ingredients. To the degree the edible films and coatings protect foods, the amount of packaging can be reduced and recyclability of the packaging waste can be improved.