PRESERVATION OF MANGO AND SOURSOP FRUIT MIX WITH NATURAL PRESERVATIVES

Abstract

Fruit juices are usually preserved with synthetic preservatives. Many consumers have, however, in recent times, expressed concern about the negative effect of synthetic preservatives. This research was therefore focused on the use of natural preservatives honey, ginger and Senegal pepper in the preservation of mango-soursop fruit juice mix. Citric acid was added to the sample used for the treatment A (control), Treatments B, C, D, and E were preserved with honey, ginger, Senegal pepper, and a mixture of ginger and Senegal pepper respectively. Physicochemical qualities such as pH, TA, and TSS were determined before and after storage at 5oC for 25 days, using standard methods. Colour parameters L* (lightness), a* (redness), and b* (yellowness) of the mango-soursop fruit juice mix were determined with a colour meter both before storage and after storage. Microbial analysis of the fruit juice mix done after storage were total viable count and yeast count. Also, after the storage period, vitamin C content of the treatments were determined. A 9-point hedonic scale with 1 as dislike extremely and 9 as like extremely with an untrained panel of twenty (20) was used to assess the preference for the various treatments before storage. The sensory qualities assessed were taste, after taste, colour, aroma, and overall acceptability. The results show that the type of preservative used influenced the pH, TA, TSS, L*, a*, and b*. The results showed that the treatments with natural preservatives honey, ginger, and Senegal pepper had more vitamin C content than the control. The total viable count of the treatments preserved with citric acid (Control) was lower than those of the natural preservatives. All the values obtained were however, below the acceptable limit for fruit juice. However, the yeast count for the control was higher than those of the treatments with natural preservatives. The treatments with natural preservatives had relatively lower preference scores in terms of most their sensory qualities and the overall acceptability. The results indicate that honey, ginger and Senegal pepper can preserve the vitamin C in mango-soursop juice mix better than the citric acid. The mangosoursop juice preserved with natural preservatives were safe for consumption. Also treatments with natural preservatives were least preferred compared to the one with citric acid. It is therefore recommended that the vitamin C content for the juice mix should be determined before and after storage to know the extent of vitamin C loss, the microbial analysis should be done for both before and after storage of the fruit juice mix, and the phytochemical components of the fruit juice mix should be assessed to appreciate its health benefits.