Biodegradable film from mango kernel starch: Effect of plasticizers on physical, barrier, and mechanical properties

Abstract

In this study, the feasibility of mango kernel starch (MKS) as a new film-forming material was studied. A filmogenic solution of MKS (2% w/v) was prepared with different plasticizers (glycerol, sorbitol, PEG-400, and a 1:1 mixture of glycerol and sorbitol) at different concentrations (40,50, 60, and 70% w/w of starch weight). The films were prepared by a casting technique and the effects of plasticizers on the physical, barrier, sorption, and mechanical properties were investigated. It was noted that glycerol, sorbitol, and their 1:1 combination produced homogeneous, transparent, and smooth films, whereas PEG-400 did not form film with appropriate characteristics. The scanning electron micrographs showed that MKS films had a uniform surface with no holes or fracture. The glycerol-plasticized films exhibited higher solubility, water vapor permeability (WVP) and elongation at break (EAB), but lower tensile strength (TS) than those obtained with sorbitol and combined plasticizers. Glycerol-plasticized films also presented high equilibrium moisture contents at all humidity levels. The TS decreased and the solubility, WVP, and EAB increased with increasing concentration of plasticizers. Low oxygen permeability (OP) was evident in sorbitol plasticized films at 40% plasticizer concentration while lower WVP values were found in combined plasticizers films.

Effect of mango kernel starch coatings on the shelf life of almond ( Prunus dulcis ) kernels

“…If the PV of 20 meq O 2 /kg assumed to be the acceptance threshold value for oil (Mat e, Frankel, & Krochta, 1996), the uncoated nuts took 50 days to become unacceptable at 40 8C, while coated almonds maintained PV below this threshold value up to 80 days except for glycerol coated nuts which showed slightly higher PV values (22.21 meq O 2 /kg of oil) than their counterparts. The lowest PV value observed for sorbitol coated nuts could be due to their low water vapor permeability as well as high oxygen barrier property reported in our previous study (Nawab et al, 2016a). According to Kranner and Karel (1990)…”

“…Due to increasing demand of renewable resources in food as well as in non-food industries, researchers have been continuously trying to explore the novel, underutilized, and low-cost sources of raw materials for better protection of food against deterioration. Among different renewable resources mango kernel starch is underutilized source of starch which is usually wasted during mango processing; in spite of the fact that most of its properties are comparable to other commercial starches (Kaur, Singh, Sandhu, & Guraya, 2004) and it could be effectively utilized not only as starch source but also for the production of biodegradable/edible films and coatings (Nawab, Alam, Haq, & Hasnain, 2016a). In biopolymer-based films and coatings production, plasticizers are essentially added since they can improve flexibility and handling of films, maintain integrity, and avoid pores and cracks in the polymeric matrix (Garcia, Martino, & Zaritzky, 2000).…”

Physicochemical characteristics, bioactive compounds and industrial applications of mango kernel and its products: A review

“…The regular shape of the granules makes it difficult to initiate a crack or a fracture in the films. Nawab, Alam, Haq, and Hasnain (2016) noted that MKS films were quite brittle and rough compared to plasticized ones, although a scanning electron micrograph showed the surface of MKS films to be uniform and without any hole or fracture. Films plasticized with glycerol and sorbitol were smooth, flexible, and transparent, indicating the compatibility of these plasticizers with MKS.…”

Nanocomposite Films from Mango Kernel or Corn Starch with Starch Nanocrystals

“…Mango kernel starch has been previously used to form films, but without any nanofillers. Some previous studies have been focused on production of starch films filled with starch nanocrystals (SNC) using traditional starch sources such as corn, waxy maize, rice, taro, and pea, as well as from a nonconventional source, amadumbe …”