Fermented Hass avocado kernel: Nutritional properties and use in the manufacture of biscuits

Abstract

In this study, the use of fermented Hass avocado kernel (FHK) with Lactobacillus plantarum to produce functional biscuits was examined. The chemical composition and antinutrient factors were evaluated for raw and fermented Hass avocado kernels. Fatty acids were separated by gas liquid chromatography. The physical properties, color, and sensory attributes of the biscuits were assessed using professional methods. The protein increased by 54% after fermentation to become (7.93%) in FHK while it was 5.15% in raw Hass avocado kernel (RHK). The crude fiber and ash decreased after fermentation by 18% and 8%, respectively. A significant (p < 0.05) increase was recorded in total phenol content, antiradical effect against DPPH and flavonoid content of FHK compared with RHK. After fermentation, reduction of tannins content was 80.76%, oxalates content 89.95%, alkaloids 70%, while traces of phytates and saponin were detected. The relative density, saponification value and iodine value of FHK oil were 0.917 g/ml, 212.26 mg KOH/g oil and 72.74 g Iodine/100 g oil, respectively. FHK oil had the following sequence: PUFA (51.54%) > SFA (26.72%) > MUFA (21.83%). The highest spread ratio (6.17) was recorded in biscuits produced by replacing 10% of FHK. Difference between the biscuit samples in the color from all treatments was completely compatible with the sensory evaluation results. Substituting 5% and 10% of FHK flour significantly improved both the brittleness and the total percentage of replacement.