Potato Peel as a Sustainable Resource of Natural Antioxidants for the Food Industry

Urszula Samotyja

doi:10.1007/s11540-019-9419-2

Abstract

Upgrading of food processing residues is currently a topic of global interest as scientists and industries have focused on using natural sources of antioxidants as an alternative to synthetic ones. The aim of the present work was to assess the potential of potato peel extracts of cultivars Gala and Jazzy in 96% ethanol, 80% ethanol and water by using antioxidant assays as well as model systems that contained food lipids. Extracts in 96% ethanol contained the highest amount of total phenolics (40.5 and 28.4 mg/g of dry weight) and showed the highest antiradical, reducing and iron-chelating potential, followed by extracts in 80% ethanol. The order of the extracts’ activity in β-carotene bleaching assay was strongly concentration-dependent. Potato peel extracts showed high efficiency in retarding oxidation of rapeseed oil, where they performed better than butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). They also delayed conjugated diene and volatile formation in sunflower oil. Compounds of potato peel extracts act via several mechanisms, assuring long-term protection of food lipids. They are a promising source of antioxidants that should be chosen carefully for a given medium in order to be stabilized and to obtain optimal results. The manner of potato peel valorization proposed here is in line with the global challenge to reduce food production waste residues and also gives an opportunity to extend the shelf life of food.

Highlights

Global intensification of food production has led to the generation of large quantities of food waste residues
The results presented here prove the high antioxidant efficiency of potato peel extracts in delaying primary oxidative processes in rapeseed oil
The results obtained in this study provide important information on the properties of both cultivar Gala and Jazzy potato peel extracts, as these are able to delay primary oxidative changes in food lipids and have a positive effect on retarding oxidative rancidity which is connected with the formation of volatile aldehydes

Summary

Introduction

Global intensification of food production has led to the generation of large quantities of food waste residues. In order to reduce the mass of agro-industrial wastes, international organizations such as the United Nations and current legislation throughout the world have begun to strongly encourage the food industry to find new end uses for residues (European Union 2012; United Nations 2015; RedCorn et al 2018). Potatoes are one of the most commonly consumed crops in the world, which is connected with their impact on residue generation. The disposal of this waste poses a challenge. Potato peels constitute a major waste of potato processing that ranges from 15 to 40% of the initial product’s mass; their valorization should be of interest to the food industry (Akyol et al 2016; Gebrechristos and Chen 2018)

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Conclusion