African Journal of Food Science Vol. 4(7), pp. 427 - 433, July  2010

ISSN 1996-0794 © 2010 Academic Journals  

Full Length Research Paper

Comparative study related to physico-chemical properties and sensory qualities of tomato juice and cocktail juice produced from oranges, tomatoes and carrots   J. Adubofuor1*, E. A. Amankwah1, B. S. Arthur1 and F. Appiah2   1Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. 2Department of Horticulture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.   *Corresponding author. E-mail: jkwab@yahoo.de.   Accepted 17 June, 2010

Abstract

Fruits and vegetables belong to an important class of foods that supply human diet with nutritive requirements including vitamins and minerals which are essential for normal body health and function. The study was carried out to determine the physico-chemical properties and sensory qualities of tomato juice and cocktail juice produced from oranges, tomatoes and carrots. Two varieties of tomatoes, known in Ghana as the Bolga and Ashanti varieties were processed into juices using the gravity method. Analysis such as total soluble solids, titratable acidity, lycopene, vitamin A and C were determined. Sensory analysis on both juices indicated that the Bolga variety was better preferred significantly (p < 0.05). Four cocktail juices were formulated in different ratios from a combination of carrots, tomatoes (bolga) and two varieties of oranges, namely late Valencia and pineapple. The juices were subjected to physico-chemical analysis after which sensory evaluation of the products was conducted to determine the preferred blend. Parameters analyzed included among others titratable acidity, total soluble solids and vitamin C. It was established from the sensory evaluation results that the cocktail juice with a formulation ratio of 60% late Valencia orange variety, 20% carrots and 20% bolga tomatoes was the most preferred blend among the 4 formulations. Further sensory preference test was carried out to compare the attributes of the preferred cocktail with a cocktail juice on the market. The results indicated a significant difference (p < 0.05) in colour, flavour and mouth feel of the two products, whereas there were no significant differences (p > 0.05) in taste, aftertaste and overall acceptability of the two products.

Key words: Physico-chemical properties, sensory qualities, tomato juice, cocktail juice.