Qualities and Aroma of Watermelon Juice during Storage at 4 °C

Abstract

Abstract. The watermelon juice was pasteurized by the ultra-high temperature treatment, and stored at 4 o C for 2 weeks. The ultra-high temperature reduced the initial microbial counts of the watermelon juice. The aroma of the watermelon juice was reduced during the storage at 4 o C for 2 weeks. The typical volatiles were reduced from 52.1 % to 37.2 % during the storage. Introduction Watermelon (Citrullus lanatus) juice provides consumers with the moisture and some physiological functions as well [1]. The intake of the watermelon juice increases the plasma concentrations of lycopene, β-carotene [2] and arginine [3,4]. Consequently, the juice reduces the chemical-induced hepatotoxicity [5] and proliferation of the cancer cell line [6] and relieves the muscle soreness of athletes [7].The ultra-high temperature technique is the conventional way to inactive the bacteria of fruit juice [8]. The UHT is not only used in milk production, but also used for fruit juices, cream, soy milk, yogurt, wine, soups, honey, and stews [9]. The UHT treatment has effectively inactivated the bacteria of the watermelon juice [10] and maintained the aroma of the sugarcane [11]. However, the qualities and aroma of the pasteurized juice during the shelf life had not been evaluated to the best of our knowledge.Therefore, the watermelon juice was pasteurized by the UHT treatment, and then stored at 4 °C . The qualities and aroma during the storage were evaluated. Material and Methods Processing of the Watermelon JuiceMature watermelon (Citrullus lanatus var. Jingxin No.3) was purchased from a local fruit market. The fruits were round with regular stripes and weighted about 3~4 kg per fruit. The flesh of the fruits was red with a soluble solid content of 11.5~13.5 %.The fruits were peeled and squeezed in a Philips juicer after stored at 4 °C for 24 h (HR1861, Philips Co. Beijing, China). The juice was mix with complex food additive including arboxymethylcellulose sodium, ascorbic acid, xanthan gum, ethylene 572 This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

Qualities of Watermelon Juice during Shelf-life

“…The juice was mixed with complex food additive including arboxymethylcellulose sodium, ascorbic acid, xanthan gum, ethylene diamine tetraacetic acid, carminum, sodium pyrophosphate and etc [9]. The mixture was fully stirred and adjusted to the pH 4.1 with the citric acid (1mol/L), and adjusted soluble solid content to 8.0 with the high fructose corn syrup (4502504-01, Fresh Juice Industry (Kunshan) Co. Ltd.).…”