Background and Objectives: In recent years, microwave heating has been increasingly popular all over the world due to the unique characteristics of microwave energy, that can be used as a suitable heat treatment. This trend also seems to be associated with increased awareness about the advantages of nutritious and healthy foods as well as functionalities of certain phytochemicals in diets, which may act as neutraceuticals. Microwave heating is known for its operational safety and nutrient retention capacity with minimal loss of heat-labile nutrients, dietary antioxidant phenols and carotenoids. The aim of this study is evaluate and explain a suitable method for production functional foods and extraction of phenolic compounds and antioxidant for Specific goals.
Materials and Methods: Grapefruit juice was concentrated to achieve the final brix 42° by two different heating methods, including conventional heating and microwave heating, at various operational pressures (7, 36, and 100 kPa). The effects of each method on total phenolic content (Folin Ciocalteo Colorimetry method), anti-oxidant activity (DPPH method) and browning index (Hunter parameters) were investigated.
Result: The study shows significant difference created by the microwave in the content of total phenolic compounds, anti-oxidant activity and color concentrates compared to rotary evaporator, at a confidence level of % 5 (05/0 = α).
Conclusion: The results showed that microwave method can be used as an appropriate method to be used in functional foods production and extraction of phytochemicals.