Wrap up with spices to ward off food spoilage

January 30, 2023

Enough has been said about anti-oxidant and anti- microbial properties of spices. But if these inherent properties can help in preventing food wastage across the globe, it is something novel and useful. It is known that, colossal quantities of food are wasted every day which is expected to increase to more than 200 million tonnes by 2050. Food, be it fresh or processed, needs packaging to protect it from the outside environment, for convenience, and to communicate information to consumers about what is inside the package. Food packaging provides protection for food from adulteration by water, gases, microorganisms, dust, and many more. Of late, traditional packaging with non-biodegradable conventional plastics is becoming more innovative and creative in tune with consumers’ demand and modern lifestyle. These new developments are collectively called active packaging.

Active packaging (AP)

Australian food packaging consultant Gordon Robertson defines AP as “packaging in which subsidiary constituents have been deliberately included in or on either the packaging material or the package headspace to enhance the performance of the package system”. It transforms the traditional passive packaging system to one of active defence and catalyses the interaction between the environment, packaging, and the product for longer shelf life and/or better quality. AP technologies include some physical, chemical, or biological action which changes interactions between a package, product, and / or headspace of the package in order to get a desired outcome. For this, sachets, pads and micro-encapsulations which are placed inside packages, and active ingredients that are incorporated directly into packaging materials are currently employed. Their mode of operation is as scavengers of oxygen, carbon dioxide, ethylene or flavour absorbers or anti-microbials. Mostly they act through controlled release often activated via pH, temperature, UV light or ‘bioswitches’.

Bio-based and biodegradable polymers such as starch, cellulose, chitosan, etc., are slowly replacing fossil-based polymers in food packaging. Biopolymer-based films have proven to be an exceptional matrix for developing AP materials with the inclusion of a variety of natural additives, such as herb extracts and essential oils. Natural antimicrobial materials combined with edible materials can prevent or control outbreaks of infectious food-borne pathogens, extend the shelf-life of food products and improve the quality and safety standards of the packaged items. Cinnamon and ginger essential oils in carboxymethyl cellulose, refrigerated beef meat coated with rosemary essential oil, polyphenols rich rosemary extracts within cassava starch films for pork meat packaging and films based on a gelatin-chitosan blend with eugenol are some examples of edible films used in food packaging.

Spices in active packaging

Having Generally Recognized as Safe (GRAS) status, essential oils (EOs) and extracts of spices can be directly added to the polymer/biopolymer matrices. Polymers like polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polystyrene (PS) have excellent properties for food packaging applications, but their disposal and end-of-life treatments have become an issue in recent years. On the other hand, biopolymers like starch, polylactic acid (PLA), waterborne polyurethane, cellulose derivatives, gums, chitosan, and proteins obtained from animal or vegetable sources are environment-friendly alternatives in active packaging applications. The bioactive compounds in spice extracts and EOs, known for their antimicrobial and antioxidant properties, get progressively released from the packaging material and interact with the packaged food, increasing their shelf life. Some of the spice based compounds and EOs with proven efficacy in active packaging of food products are listed in the table given below.

Examples of spice extracts and essential oils used in food packaging

Conclusion

Research on innovative packaging by incorporating natural active agents is flourishing since the last few years. Spices containing various bioactives like flavonoids, terpenoids and polyphenol exert antioxidant, antimicrobial activity and also extend the shelf-life of the product thus can replace the usage of synthetic preservatives in food. Most of these studies are based on Mediterranean spices like rosemary, oregano, sage, etc., and many of the Indian spices like black pepper, cardamom and turmeric are not extensively tested for such applications. Another approach is the development of composite films or multicomponent films to take advantage of their multiple beneficial properties. However, some regulations are needed on using spice bioactives in food packaging as some spice compounds are reported to have adverse effects. More research is needed in this sector at least as an alternative to plastics.

Additional Reading

  • Flores, Y. et al. 2021. Use of herbs and their bioactive compounds in active food packaging. In: Aromatic Herbs in Food, pp.323-365. Elsevier Inc.

  • Ravi, K. et al. 2020. Spice bioactives in edible packaging. Journal of Spices and Aromatic Crops 29(2): 81-97. https://doi.org/10.25081/josac.2020.v29.i2.6507

  • Valdés, A. et al. 2015. Use of herbs, spices and their bioactive compounds in active food packaging.” RSC Advances 5, 40324-40335. https://doi.org/10.1039/C4RA17286H

  • Vilela, C. et al. 2018. A concise guide to active agents for active food packaging. Trends in Food Science & Technology 80: 212-222. https://doi.org/10.1016/j.tifs.2018.08.006

[Published in Spice India July 2022]