Food preservation techniques and nanotechnology for increased shelf life of fruits, vegetables, beverages and spices: a review

Abstract

Food wastage is a major issue impacting public health, the environment and the economy in the context of rising population and decreasing natural resources. Wastage occurs at all stages from harvesting to the consumer, calling for advanced techniques of food preservation. Wastage is mainly due to presence of moisture and microbial organisms present in food. Microbes can be killed or deactivated, and cross-contamination by microbes such as the coronavirus disease 2019 (COVID-19) should be avoided. Moisture removal may not be feasible in all cases. Preservation methods include thermal, electrical, chemical and radiation techniques. Here, we review the advanced food preservation techniques, with focus on fruits, vegetables, beverages and spices. We emphasize electrothermal, freezing and pulse electric field methods because they allow both pathogen reduction and improvement of nutritional and physicochemical properties. Ultrasound technology and ozone treatment are suitable to preserve heat sensitive foods. Finally, nanotechnology in food preservation is discussed.

Keywords: Electrothermal; Food preservation; Freezing; Nanotechnology; Ozone treatment; Pulse electric field; Ultrasound.

Fig. 1

Food wastage for different food materials based on weight percentage. The demand for variety and abundance as well as inefficient storage conditions increases the amount of overall food wastage. Fruits and vegetables are among the least expensive and fastest spoiling foods followed by milk and dairy products. Data from ReFED (2016)

Fig. 2

Types of ultrasound treatments: bath sonicator and probe sonicator. The treatment works on the principle of cavitation in which there is an energy transfer among food particles leading to bubble formation and collapsing. The technique requires minimal power providing more efficiency than traditional drying methods. It is used for treating various powdered or liquid foods

Fig. 3

Thermosonication processing generally used for treating milk and wine samples for improving the shelf life. The treatment can prove to be cost-effective with reduced processing temperature due to the use of sonication as compared to conventional heat treatment or addition of synthetic preservatives

Fig. 4

Application of pulse electric field generally used for treating liquid foods and pastes. The technique is a nonthermal food preservation method involving usage of pulses of electricity into the food material. The treatment gives high quality food with almost no change in texture or quality thus maintaining the original taste of food

Fig. 5

Applications for nanotechnology in agriculture, food processing and packaging. Nanotechnology has gained a lot of interest with versatile applications and unique properties enabling efficient processes and quality products. The use of nanomaterials, nanosensors, precision agriculture and advanced packaging can play a promising role in improving the food sector