کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4564010 | 1330918 | 2011 | 9 صفحه PDF | دانلود رایگان |

The physical properties of fresh highbush blueberry epicarp were determined in order to increase the effectiveness of chitosan-based coatings. The measured roughness of the blueberry epicarp was 42 ± 10 μm. The surface free energy, γSV of blueberry epicarp with and without epicuticular wax was calculated using the “acid-base” theory. Blueberry epicarps with or without wax have mainly an apolar (Lifshitz–van der Waals) character with a small polarity (Lewis acid-base). In both cases, blueberry surface is a low-energy surface. With wax γSV = 29.1 ± 0.1 mJ m−2 while after the wax removal, γSV was increased significantly to 38.3 ± 2.8 mJ m−2. Various chitosan-based coatings were applied to the blueberry epicarp. The surface tension, the cohesive energy and the spreading coefficient were calculated for each solution. In particular, the effects of concentration of a plasticizer (glycerol) and a surfactant (Tween 20) on the wetting of blueberry epicarp were studied. A mathematical relationship between concentrations and spreading coefficient S was proposed. Finally, the optimal concentrations of chitosan-based solutions were determined according to S.
Journal: LWT - Food Science and Technology - Volume 44, Issue 6, July 2011, Pages 1449–1457