STUDY OF THE KINETICS OF DRYING OF FOLATE-CONTAINING COMBINED RAW MATERIALS

Abstract

Every year, the preservation of nutrients and energy resources becomes increasingly important in the processing of plant raw materials worldwide.

Vegetables are a staple food because they are rich in fibre, minerals, vitamins and antioxidants.

Folate is a water-soluble B vitamin that plays a vital role in cell growth and development. The names folic acid and folate come from the Latin word folium, meaning ‘leaf,’ and it was first isolated from spinach leaves in 1941.

Folic acid is naturally present in high concentrations in leafy vegetables such as spinach, lettuce, cabbage, broccoli, asparagus, tomatoes, leeks, wild garlic, green onions, fruits, legumes (green beans, beans, peas, lentils), nuts, yeast, mushrooms, and animal products.

Spinach (Spinacia oleracea L.) is an annual leafy green plant rich in beta-carotene (provitamin A), folic acid (vitamins A and C), minerals (phosphorus, sodium and potassium) and dietary fibre.

Green beans are young, immature fruits of various varieties of common beans (Phaseolus vulgaris). In 100 grams (3.5 ounces) of raw green beans, there are 31 calories and a moderate amount (10-19% of the daily value) of vitamin C, vitamin K, vitamin B6, and manganese, as well as a rich amount of folic acid (vitamin B9).

Vegetables spoil quickly after harvesting and are only consumed during the growing season. They are often sold canned or frozen.

Drying is one of the preservation methods that allows extending the shelf life of plant raw materials while preserving their vitamin content and preventing the growth and production of microorganisms that cause rotting.

Various methods can be used to dry these raw materials, namely convective, sublimation, microwave, spray drying and various combined methods.

Convective drying is one of the most common methods for processing dark green leafy vegetables.

To stabilise folates, plant raw materials must be combined with raw materials that are high in vitamin C.

The aim of the work is to study the kinetics of drying folate-containing combined raw materials, namely a mixture based on spinach, dill, parsley and a mixture based on green beans and green onions.

The work studies the drying kinetics of folate-containing combined raw materials, namely a mixture based on spinach, dill, parsley, and a mixture based on green beans and green onions.

It was determined that when drying a mixture based on spinach, dill and parsley, the duration and nature of the curves are close to the results obtained in the study of parsley.

It has been determined that increasing the temperature from 60 to 70ºC when drying a mixture based on green beans and green onions intensifies the process by 21%. The use of low heat transfer temperatures is confirmed by the fact that when drying at 60ºC, folate preservation is 3.9 times higher than at 100ºC.