Valorisation of fruit peel bioactive into green synthesized silver nanoparticles to modify cellulose wrapper for shelf-life extension of packaged bread. (February 2023)

• Record Type: Journal Article
• Authors: Gopalakrishnan, Krishna; Chandel, Mahima; Gupta, Vanshita; Kaur, Kuljinder; Patel, Ajay; Kaur, Kamaljit; Kishore, Anand; Prabhakar, Pramod K.; Singh, Anurag; Shankar Prasad, Jai; Bodana, Vikrant; Saxena, Vikas; Shanmugam, Vijayakumar; Sharma, Arun
• Is Part Of: Food research international. Volume 164(2023)
• Publication Date: 2023-02
• Subjects: Fruit peel extract -- Green synthesis -- Silver nanoparticles -- Cellulose wrapper -- Food packaging; AgNPs silver nanoparticles -- AOA antioxidant activity -- FTIR spectroscopy Fourier-transform infrared spectroscopy -- NPs nanoparticles -- OPC oxygen permeability coefficient -- PC total plate count (microbial load) -- PM-C untreated 'control' cellulose wrapper -- PM-P and PM-K modified cellulose wrappers enrobed with green synthesised AgNPs from pomegranate peel extract and kinnow peel extract respectively -- RH relative humidity -- RSA radical scavenging activity -- SEM scanning electron microscopy -- TFC total flavonoid content -- TPC total phenolic content -- UHPLC-PDA ultrahigh performance liquid chromatography-photodiode array -- UV–vis spectroscopy ultraviolet–visible spectroscopy -- WVPC water vapour permeability coefficient -- WVTR water vapour transmission rate -- YMC yeast and mould count; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2022.112321
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: Fruit peel bioactive were valorised into green synthesised silver nanoparticles (AgNPs). The characterisation of AgNPs confirmed successful synthesis of nanoparticles. The cellulose wrappers were modified by enrobing synthesized AgNPs only one side of cellulose wrapper. The characterisation of modified cellulose wrappers indicated low oxygen permeability and hydrophobicity. A seven days storage study of bread packaged in modified cellulose wrappers revealed delayed incidence of microbial load as compared to untreated cellulose wrapper. Abstract: Fruit peels are rich source of bioactive compounds such as polyphenols, flavonoids, and antioxidants but are often discarded as waste due to limited pharmaceutical and nutraceutical applications. This study aimed to valorise pomegranate and citrus fruit peel into green synthesised silver nanoparticles (AgNPs) in order to modify cellulose-based wrapping material for prospective food packaging applications and propose an alternate and sustainable approach to replace polyethene based food packaging material. Four different concentrations of AgNO3 (0.5 mM, 1 mM, 2 mM, and 3 mM) were used for green synthesis of AgNPs from fruit peel bioactive, which were characterised followed by phytochemical analysis. Ultraviolet–Visible spectroscopy showed surface plasmon resonance at 420 nm, XRD analysis showed 2θ peak at 27.8°, 32.16°, 38.5°, 44.31°, 46.09°, 54.76°, 57.47°, 64.61° and 77.50° corresponding to (2 1 0), (1 2 2), (1 1 1), (2 0 0), (2 3 1), (1 4 2), (2 4 1), (2 2 0) and (3 1 1) plane of face centred cubic crystal structure of AgNPs. Fourier-transform infrared spectroscopy analysis of AgNPs green synthesised from pomegranate and kinnow peel extract showed a major peak at 3277, 1640 and 1250–1020 1/cm while a small peak at 2786 1/cm was observed in case of pomegranate peel extract which was negligible in AgNPs synthesized from kinnow peel extract. Particle sizes of AgNPs showed no statistically significant variance with p > 0.10 and thus, 2 mM was chosen for further experimentation and modification of cellulose based packaging material as it showed smallest average particle size. Zeta potential was observed to be nearly neutral with a partial negative strength due to presence of various phenolic compounds such as presence of gallic acid which was confirmed by ultrahigh performance liquid chromatography-photodiode array (UHPLC-PDA) detector. Thermal stability analysis of green synthesised AgNPs qualified the sterilisation conditions up to 100 °C. AgNPs green synthesized from both the peel extracts had higher polyphenolic content, antioxidant and radical scavenging activity as compared to peel extracts without treatment (p < 0.05). The cellulose based food grade packaging material was enrobed by green synthesised AgNPs. The characterisation of modified cellulose wrappers showed no significant difference in thickness of modified cellulose wrappers as compared with untreated cellulose wrapper (p > 0.42) while weight and grammage increased significantly in modified cellulose wrapper (p < 0.05). The colour values on CIE scale (L*, a* and b*) showed statistically significant increase in yellow and green colour (p < 0.05) for modified cellulose wrappers as compared to control wrapper. The oxygen permeability coefficient, water vapour permeability coefficient, water absorption capacity and water behaviour characteristics (water content, swelling degree and solubility) showed significant decrease (p < 0.05) for modified cellulose wrapper as compared to control wrapper. A uniform distribution and density of green synthesised AgNPs across cellulose wrapper matrix was observed through scanning electron microscopy (SEM) images with no significant aggregation, confirming successful enrobing and stable immobilisation of nanoparticles from cellulose matrix. A seven-day storage study of bread wrapped in modified and control cellulose wrappers showed delayed occurrence of microbial, yeast and mould count in bread packaged in modified cellulose wrappers and thus, resulting in shelf life extension of bread. The results are encouraging for the potential applications of modified cellulose wrappers to replace polyethene based food packaging.