ACHIEVING OF FUNCTIONAL INGREDIENT FROM APPLE WASTES RESULTING FROM THE APPLE JUICE INDUSTRY

Abstract

At industrial level, by apple processing into juice results significant amounts of waste, representing 25-40% of the mass of processed apple depending on the technology applied for juice extraction. At European level, by apple processing into juice results annual millions of tonnes of waste. Apple waste is a rich source of food fibres (cellulose, hemicellulose, lignin, pectin), minerals (calcium, magnesium, potassium, zinc, iron, etc.), phenolic compounds, mainly phenolic acids such as chlorogenic acid, protocatechuic acid and caffeic acid and flavonoids. Also, apple waste contains simple sugars (glucose, fructose and sucrose). In this paper are presented the results of the research performed to achieve a functional ingredient (powder) from apple waste resulting in apple juice industry. For this purpose, apple waste (Jonathan, Golden Delicious and Red Delicious varieties) was subjected to a convective drying process at 50°C to protect the bioactive compounds (vitamins, phenolic compounds, etc.) to a moisture content to allow their milling and turning them into powder and their stability in terms of quality. The achieved functional ingredient was evaluated sensory, physic-chemically and microbiologically. Powder achieved from apple waste is characterized by total dietary fibre (60.62...64.75%), iron (2.31....2.73 mg/100 g), potassium (450.12... 508.45 mg/100 g), calcium (76.32 ....92.44 mg/100 g), magnesium (41.15....55.65 mg/100 g) and total polyphenol content (17.83 ...38.83 mg GAE/g). At the same time, powder achieved from apple waste has antioxidant potential. Due to its complex biochemical composition and antioxidant potential, the functional ingredient achieved from apple waste can be used to fortify bakery and pastry products.