Large scale solar food processing under investigation

One of the major obstacles to the roll-out of such technology is lack of interaction between those developing it and food manufacturers, states ‘Solar energy in food processing – a critical appraisal’.

“Solar energy-based technologies are currently playing an important role in food processing,”​ write the researchers. “However, at present their use is limited to micro-to small-scale processing. The feasibility of using them on a large scale can and should be studied and is the goal of future studies.”​

The authors recognize that the cost of investing in such research is high, but acknowledge that government incentive schemes are available to mitigate the expense.

Lack of awareness​

They claim the major barrier to take-up is not lack of funding, but lack of awareness. That’s despite “an urgent need to integrate the food processing industry with solar equipment developers … through governmental, international agencies as well as the expert bodies in these fields”.​

The research covers a range of examples of the viable use of solar-based processing methods, focusing on activities in India, where the authors are based.

These include use of Solar Dryers, which are quicker and more hygienic than using natural sunlight in open sun drying, a practice also used in India. “Solar dryers can be used for 250-300 days a year in most southern parts of the country,”​ the study states.

Variety of applications​​

“In recent years many solar gadgets have been developed for a variety of applications in food processing,”​ it continues. “Different solar concentrators and box ovens provide boiling, steaming, blanching and roasting capabilities while solar air dryers/heaters do the work of moisture removal.”​

Solar concentrators of 2.3m in size have been used for boiling Indian Gooseberry for use in foods such as Amla Candies and Amla Pickles in India.

Examples are given of solar processes underway in other countries, ranging from solar roasting of peanuts in Burkina Faso to use of solar energy to process marmalade and pasteurize fruit juice in Paraguay.

Frito Lay​

The review also notes Frito Lay’s installation of a five-acre solar concentrator field in 2008 to make its Sun Chips in Modesto, California.

The authors note claims made on the company’s website that the technology was able to cut the amount of electricity needed to make each bag of crisps by 22%. Frito Lay also aims to make its US plant in Casa Grande, Arizona, completely dependent on solar energy.

India’s Society for Energy, Environment and Development, aided by funding from the United Nations Development Programme, had developed a commercial solar cabinet dryer from an initial prototype, they state. This had been used to make Mango Bars.

The device has been used to produce more than 60 products for various food groups, including fruit bars and slices, herbs and spices, the researchers write.

Source: ‘Solar energy in food processing – a critical appraisal’​; Journal of Food Science and Technology, April 2013, Volume 50, Issue 2, pp209-222; doi: 10.1007/s13197-012-0739-3​;

Authors: Amruta Eswara & M. Ramakrishnarao, Society for Energy, Environment and Development, Hyderabad, India