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Chitin is a versatile environmentally friendly modern material. It has a wide range of applications in areas such as water treatment, pulp and paper, biomedical devices and therapies, cosmetics, membrane technology and biotechnology and food applications. Crustacean waste is the most important chitin source for commercial use. Demineralization is an important step in the chitin purification process from crustacean waste. The conventional method of demineralization includes the use of strong acid (commonly HCl) that harms the physiochemical properties of chitin, results in a harmful effluent wastewater and increases the cost of chitin purification process. The current study proposes the use of organic acids (lactic and acetic) produced by cheese whey fermentation to demineralize microbially deproteinized shrimp shells. The effects of acid type, demineralization condition, retention time and shells to acid ratio were investigated. The study showed that the effectiveness of using lactic and/or acetic acids for demineralization of shrimp shells was comparable to that of using hydrochloric acid. Using organic acids for demineralization is a promising concept, since organic acids are less harmful to the environment, can preserve the characteristics of the purified chitin and can be produced from low cost biomass such as cheese whey. In addition, the resulted organic salts from the demineralization process can be used as a food preservative and/or an environmentally friendly de-icing/anti-icing agents

The effectiveness of ultraviolet radiation for on-line sterilization of cheese whey was investigated. The effects of flow rate and residence time on the performance of three UV reactors having different gap sizes (18, 13, and 6 mm) were studied. Six flow rates and six residence times were tested with the three UV reactors. The cheese whey used in this study had a very high turbidity (4317 NTU), very poor transmittance in the UV radiation germicidal range ( approximately 0%), and high percentage of large solid particles ( approximately 20% > 100 microm). Although the cheese whey physical characteristics showed low probability of sterilization using UV radiation, the study showed that UV radiation can be used on-line to sterilize cheese whey if the proper reactor gap size and the appropriate residence time are used. There were combined effects of the flow rate and gap size. The cell removal efficiency increased with increases in residence time and decreases in the UV reactor gap size. Removal efficiency of 100% was not achieved in this study with the first UV reactor (18-mm gap size), whereas 100% removal efficiency was achieved with the second (13-mm gap size) and third (6-mm gap size) UV reactors at residence times of 2.0 and 0.5 h, respectively. The microbial decay rates achieved in this study were 4.94, 7.62, and 20.9 h(-)(1) using the first, second, and third UV reactor, respectively. Residence times of 3.3, 2.1, and 0.8 h would be required to completely destruct a microbial population of 5.95 x 10(6) cells/mL using the first, second, and third UV reactors, respectively. Although cheese whey sterilization using UV radiation seems to be a good alternative to pasteurization, increases in cheese whey temperature resulted in lamp fouling. If online sterilization is to be used, the fouling problem should be investigated and a maintenance scheme for the UV reactor should be developed.

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