Extraction and physicochemical characterization of insect oils obtained from Acheta domesticus & Tenebrio molitor


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2019

Öğrenci: AHMET ERDEM UĞUR

Danışman: HAMİ ALPAS

Özet:

Edible insects have become one of the most attracted and attention-grabbing alternative food sources in recent years due to the constituents that include proteins, oils, carbohydrates, minerals and vitamins. The goal of this study is to explore insect oils in terms of physicochemical properties to help their utilization in future against the possible scarcity of the resources in the world, and the most important point is to help to enable these valuable edible insect species as one of the main nutrient sources of the human being. In this study, oil portion of the two edible insect species, Tenebrio molitor (yellow mealworm) and Acheta domesticus (house cricket) were focused and it was investigated how the physicochemical properties of the oil changed with different extraction conditions. The oil content of Tenebrio molitor and Acheta domesticus are >34 and >28% respectively and they include significant amount of Ω-3 and Ω-6 fatty acids that are important for the diet and they are also rich in antioxidants and phenolics that help to fight against health problems. In this study, High Hydrostatic Pressure (HHP) was used and the effect of HHP on extraction was compared with the conventional methods. Following the extraction of oil, fatty acid composition, peroxide value, crystallization and melting points, total phenolic content and the antioxidant activities were determined. Besides, it was examined how the HHP affected the composition of insect oils obtained from the two species. Oil yield was found in the range of %22.75-24.22 and %16.17-18.09 for mealworm and cricket, respectively. It was also found that the amounts of myristic acid, palmitoleic acid and linolenic acid in mealworm and cricket oils were relatively high, although the most abundant fatty acids found in both insects were palmitic acid, stearic acid, oleic acid and linoleic acid. Moreover, the difference between crystallization and melting point of mealworm were found to be higher than the cricket. The amount of unsaturated fatty acids in mealworm oil was almost two fold of saturated fatty acids, whereas this ratio was less in cricket oil.