Assessment of Nutrient and Storage Stabilizing Potential of Ginger and Garlic on Composite Fruit Smoothies

Aims: The study aimed at demonstrating the influence of natural spices (ginger and garlic) and storage conditions on nutritional, microbial and organoleptic characteristics of composite fruit smoothies.

Study Design: Completely Randomized General Factorial Design and Multivariate Pattern Recognition Technique were used to achieve the study.

Place and Duration of Study: The study took place at the Department of Food Science and Technology, Federal University of Technology, Akure between January and May 2018.

Methodology: Smoothies were produced from the blends of pineapple, watermelon and banana, treated with garlic and ginger, bottled, pasteurized and stored for 21 days to obtain a total of 12 samples and 2 control (prior to storage). Chemical parameters such vitamin C, total phenol, total sugar, moisture and crude fibre contents, titratable acidity, pH, minerals (calcium, sodium, potassium and magnesium), microbiological and sensory qualities were monitored weekly throughout the storage periods.

Results: Univariate data analysis results showed type spices as the most significant factor (p = 0.05) with respect to variables considered. There was a decline in vitamin C, titratable acidity and pH as storage time advanced. Total and reducing sugars and oBrix increased with storage while other chemical parameters did not change significantly. Garlic and ginger extracts enhanced microbial stability and contributed to better sensory acceptability of the samples. Principal component analysis (PCA) multivariate model further showed the distinct trends between the impacts of garlic and ginger on the score and loading plots. Smoothies enriched with garlic had comparatively higher TPC, crude fibre, pH, vitamin C, sodium and its ratios with potassium and magnesium, within the first week, total and reducing sugars on the third week. Conversely, ginger enriched smoothies were high in acidity, sensorial scores, magnesium and potassium in the first week of storage and oBrix afterward.

Conclusion: Garlic and ginger are potent natural preservatives with additional nutritional benefits that could replace synthetic additives.