Physicochemical and sensory properties of fermented milk supplemented with sundried African horned melon

Abstract

African horned melon (AHM) (Cucumis metuliferus), indigenous to Kenya. It contains high polyphenol and antioxidant content, yet remains underutilized in food products. This study sought to increase the utilization of AHM by developing a supplemented milk product and evaluating the effects of sundried AHM powder on the physicochemical and sensory properties of the fermented milk product. The fermented milk was supplemented with three different forms of AHM powder: whole fruit, peel, and seed, at concentrations of 0.5%, 0.7%, and 1% w/v. Physicochemical parameters such as pH, total titratable acidity (TTA), syneresis, texture, and viscosity were measured, alongside sensory acceptability assessments. Statistical analysis demonstrated significant differences (p < 0.05) in physicochemical and sensory properties between the control (did not contain AHM) and supplemented samples, particularly at higher concentrations and extended storage periods. The inclusion of AHM powder markedly influenced the fermented milk's properties, with increased TTA and syneresis in samples with higher melon powder concentrations. TTA ranged between 0.32% and 0.46% among all samples during storage which were comparatively higher than the recommended values for fermented milk products at 0.3%. pH findings range was 4.22 and 4.58. The pH range between 4.2 and 4.6 is recommended by FDA for fermented milk. Syneresis were between 2% and 13%. Texture was between 1.24 and 3.95 N. Viscosity was between 1.67 and 3.87 cP. Sensory scores ranged from 8.00 to 2.67 during storage. Fruit seed powder (FSP1) recorded the lowest amount of pH. Control maintained a higher score in the sensory attributes.