Development and Characterization of Active Native and Cross-Linked Pearl Millet Starch-Based Film Loaded with Fenugreek Oil

Sanju Bala Dhull,Preeti Dhandhi,Sneh Punia Bangar,Ranjan Deswal,Alexandru Rusu,Manish Kumar,Monica Trif

doi:10.3390/foods10123097

Abstract

In this study, cross-linked pearl millet starch and fenugreek oil was used to develop active starch edible films to overcome the limitations of native starch and to substitute artificial preservatives with natural one. The starch was cross-linked at three levels (1%, 3% and 5%) using sodium trimetaphosphate (STMP), and physicochemical properties were studied. Moreover, a comparative study was conducted among four samples of films prepared using native starch, cross-linked starch, and native and cross-linked starch loaded with fenugreek oil for physical, thermal, mechanical, morphological, and antibacterial properties. The solubility, swelling, and amylose content of native and modified starch varied from 11.25–12.75%, 12.91–15.10 g/g, and 8.97–16.55%, respectively. The values of these parameters were reduced as the concentration of STMP increased. Cross-linked starch films showed lower moisture, solubility, water vapor permeability(WVP), and elongation at break (EB) values while having higher thickness, opacity, thermal, and tensile strength values. The microscopic images of cross-linked starch films showed smooth surfaces and the absence of ridges, pores, and cracks. The films loaded with fenugreek oil showed different results; the moisture content, water solubility, and tensile strength were decreased while thickness, opacity, WVP, and EB were increased. The onset temperature and peak temperature were lower, while enthalpy of gelatinization was increased to a greater extent than films without oil. The addition of fenugreek oil to films showed a good inhibition area of 40.22% for native+oil films and 41.53% for cross-linked+oil films % against Escherichia coli. This study confirmed the successful utilization of fenugreek oil as a very effective antimicrobial agent in preparing edible films.

Highlights

There is a rising concern for using petroleum-based plastics for food packaging as they are non-biodegradable, leaving long-lasting environmental problems
The emissions from burning these plastics result in the release of greenhouse gases, which results in environmental issues such as global warming, which affects all forms of life [2]
The result showed a significant reduction in the amylose content of the cross-linked starch compared to the native starch

Summary

Introduction

There is a rising concern for using petroleum-based plastics for food packaging as they are non-biodegradable, leaving long-lasting environmental problems. The degradation of these polymers on earth typically leads to the toxicity of the environment. Starches are considered a very efficient base for decomposable plastic films due to their low raw material cost and easy availability. They can be processed with available plastic-processing equipment [3,4]. Many efforts have been made to find alternatives and ecological substitutes that can replace plastic packaging, and as a solution, starch films may be used [5]

Methods

Results

Conclusion