Effects Of Jincheng Orange Juice Qualities With Mechanical Damage

Jincheng is one of citrus fruits with special flavor, high nutritional and large planted area. It's an excellent processing variety of citrus juice. With the increasing consumption of citrus juice in our country, the improvement of citrus juice's quality of citrus juice has become the critical element in our citrus fruits processing industry. In the current study, the volatile components in Jincheng fruit with mechanical damage were captured and evaluated by Solid Phase Microextraction- Gas Chromatography-Mass Spectrometry (SPME-GC-MS). In the meanwhile, the microbial species in Jincheng were researched and the quality indicators of Jincheng were analyzed with simulative inoculation of the separated microbial species. With the analysis, the results of effects with microbes to quality indicators of Jincheng with mechanical damage were achieved. The major results are as follows:1. Analysis of volatile components of the samples with different treatments. Five samples were determined for volatile components and 109 volatile components of samples were detected. The volatile components were mainly comprised of terpenes, alcohols and esters. With the principal component analysis(PCA), it was found that the major volatile components wereβ-myrcene,δ-cadinene,1,3,8-p-menthatriene, 2-camphene,3-hexen-l-ol(E)-,4-terpineol,α-terpineol,β-linalool,β-terpineol, trans-p-mentha-2,8-dienol, ethyl acetate, ethyl caprylate, methyl hexanoate, DOA dioctyl akipate, methyl butanoate,4-hydroxy-methyl valerate,3-hydroxy-ethyl caproate, carvone, dihydrocarvone,2-pentanone, phytane.2. Isolation and identification of the strains. Four strains were obtained by isolated and identified from Jincheng fruit with spoilage. Based on results of the characteristics of morphology, physiology, biochemistry and the analysis of 16S rDNA,18S rDNA with PCR, they were identified as Bacillus coagulans, Pediococcus pentosaceus, Cryptococcus albidus and Candida albicans.3. Effects of evaluation indicator of orange juice's qualities with isolated strains. The volatile components in Jincheng with cultivated by Bacillus coagulans, Pediococcus pentosaceus, Cryptococcus albidus and Candida albicans were found that D-limonene,β-myrcene, valencene,4-terpineol, ethyl acetate, ethyl caproate,3-hydroxy-ethyl caproate, 2,4-bis(1,1-dimethylethyl)-,phenol in all sample. The contents of reducing sugar, total sugar, soluble solid in juice were dropped and the pH, contents of total acid were enhanced.With the analysis of evaluation indicator of orange juice's qualities, it was found that Bacillus coagulans impactedβ-myrcene and reducing sugar mostly; Pediococcus pentosaceus impacted ethyl acetate mostly; Cryptococcus albidus impacted 3-hexen-l-ol(E)- mostly; Candida albicans impacted carvone mostly.