Influence of Rice Bran Wax Coating on the Physicochemical Properties and Pectin Nanostructure of Cherry Tomatoes
The effects of rice bran wax coating on the physicochemical properties such as firmness, weight loss, titratable acidity (TA) and soluble solid content (SSC) of cherry tomatoes were studied during cold storage. The chemical and nanostructure properties of chelate-soluble pectin (CSP) were also investigated by high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). The results indicated that there was no significant difference of firmness between control (2.48 N) and waxed (2.87 N) fruits at the end of storage (20 days), while the weight loss of waxed fruits (13.54%) was lower than that of control fruits (16.02%). And the degree of esterification (DE) of both fruits decreased after cold storage by FTIR. The structural analysis by atomic force microscopy (AFM) indicated that rice bran wax coating inhibited the degradation of CSP. The CSP molecular widths ranged from 15 to 250 nm, and the vertical heights varied from 0.2 to 2.0 nm. Greater frequency (F q ) of large width and length CSP was found in waxed fruits than in control fruits. The results suggest that rice bran wax coating was an effective way to preserve fresh fruits.
KeywordsRice bran wax Fruit coating Chelate-soluble pectin Cherry tomato Edible coating Atomic force microscopy Nanostructure
The authors acknowledge the financial support by the Singapore Ministry of Education Academic Research Fund Tier 1 (R-143-000-583-112) and the National University of Singapore start-up grant (R-143-000-561-133). Projects 31371851 and 31071617 are supported by NSFC, Natural Science Foundation of Jiangsu Province (BK20141220), and the Applied Basic Research Project (Agricultural) Suzhou Science and Technology Planning Programme (SYN201522), and the Technology Innovation Talent Fund by Henan University of Technology (2014CXRC01) also contributed to this research.
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