International Journal of Plant & Soil Science

Aims: This study was performed to choose or select the best cultivars of longan fruit (Wuyuan, "Wu" and Kohala, "Ko"). Longan is an untraditional new crop fruits recently grown in new reclaimed areas. Besides, to investigate the possibility of preserving those aforementioned fruits
Study Design: About 20Kg of longan cultivars namely Wuyuan (Wu) and Kohala (Ko) were used in this study which has been recently performed by (HRI), harvest at suitable stage of maturity. Cultivars were obtained from Horticultural Research Institute (HRI). The cultivars were peeled and put in glass jars, then covered with high fructose corn syrup plus sucrose to obtain final concentration of 40%.
Place and Duration of Study: Department of horticulture research. Food Technology Research Institute. Agriculture Research Center, between June 2011 and November 2013.
Methodology: Soaking in different concentrations of High Fructose Corn Syrup (HFCS) plus sucrose, then stored at ambient temperature (25±2ºC) in glass jars for six months. As well as studying the influence of storage at ambient temperature (25±2ºC) on chemical and physical properties of the processed product. The effect of preservation using (HFCS and sucrose) solution to final concentration (40%) on the quality attributes during storage was investigated.
Results: The obtained results revealed that longan (Wu) cultivar soaked in (HFCS and sucrose by 1: 3, 3: 1 and 40% HFCS) solution were found to be the best products. The obtained data also revealed that longan cultivar (Wu) had the highest palatability of sensory attributes scores especially color, taste, texture, odor and overall palatability when treated as follows: (HFCS): sucrose (3:1) (treatment No. 3) and 1 : 3 (treatment No. 1) and HFCS 40% (treatment No. 4), respectively. The results also ascertained that fresh as well as stored longan cultivars (Wu) had the highest values for qualitative characteristics, sugars, T.S.S., ascorbic acid, hunter color measurements and cyaniding 3 glucoside, compared to the other studied cultivar (Ko). This could be attributed to the addition of HFCS syrup to longan fruit. Dehulled of (Wu) cultivar were found to have the most amounts of (ascorbic acid, T.S.S. and attractive lightness color measurements) after soaking in HFCS plus sucrose solution as well as during storage in glass jars up to 6 months at ambient temperature (25±2°C). So, "Ko" and "Wu" longan cultivars packed in glass jars covered with the aforementioned sugar HFCS solution retained their quite palatable, qualities during storage at ambient temperature for up to 6 months. All investigated samples maintained their original sensory properties up to 6 months.
Conclusion: Thus, the technological trend for utilization of large quantities cultivated of longan fruits in new reclaimed areas is a matter of great importance. This would lead to produce new untraditional products passing high nutritional value plus high quality of sensory attribute greeting new work opportunities by establishing a factory to produce those aforementioned new products either for local or abroad consumption must be put in consideration through that investigation. Also, the utilization of high fructose corn syrup for the production of canned longan could be recommended to replace sucrose. This replacement would reduce sucrose consumption as well as the cost of production