INFLUENCE OF WATER ACTIVITY ON PELLICLE CHAFFING, COLOR AND BREAKAGE OF WALNUT (JUGLANS REGIA) KERNELS
暂无分享,去创建一个
The moisture sorption charcteristics of walnut kernel at 27 and 37 degree C and that of the pellicle at 27 degree C were determined. The equilibrium moisture content of the pellicle at water activities studied was much higher than that of the kernel, however, its water activity at the BET monolayer moisture level was close to that of the kernel. Storage studies of the kernels equilibrated to different RH indicate that the kernel colour and flavour, as indicated by TBA value, were more stable at a moisture content of 3.2 to 3.6% rather than at the monolayer level of 2.2%. Vibration and drop tests on kernels equilibrated to different RH's indicated that pellicle chaffing and kernel breakage decreased with water activity of the kernel particularly above 58% RH. Pellicle chaffing which occurs mostly during handling and transportation of the kernels can be minimized by maintaining the kernels around 58% RH during handling and transportation. Subsequently the moisture content can be brought down to 3.2 to 3.6%, which is the optimum range for storage of kernels.
[1] D. C. Holland. Determination of malonaldehyde as an index of rancidity in nut meats. , 1971, Journal - Association of Official Analytical Chemists.
[2] L. Rockland,et al. Saturated Salt Solutions for Static Control of Relative Humidity between 5° and 40° C. , 1960 .
[3] L. Rockland. A NEW TREATMENT OF HYGROSCOPIC EQUILIBRIA: APPLICATION TO WALNUTS (JUGLANS REGIA) AND OTHER FOODSa , 1957 .
[4] J. H. Mitchell,et al. Measurement of oxidation in dried milk products with thiobarbituric acid , 1955 .