| Summary: | 碩士 === 國立宜蘭大學 === 動物科技學系碩士班 === 97 === Royal jelly (RJ) a neutraceutical bee product is suffered from labile activity during normal storage condition. At present, the suitable marker to evaluate its freshness is still lacked. Fresh RJ needs to be storage by frozen, that could be caused inconvenient consuming. Therefore, using lyophilization technique to produce RJ powder is developed in industry. The strong hygroscopic property and bad taste for RJ powder need to be improved by using starch or lactose as carriers. The purpose of this study is to identify the 57 kDa protein in royal jelly, as well to evaluate whether it could be as a freshness marker for lyophilized RJ powder. In addition using this marker and several physical-chemical properties including examine browning tendencies, pH and powder shape to evaluate storage stability of formulated RJ powder in adding yeast-fermented goat milk extract as carrier.
The isolated 57 kDa protein was analyzed by native-electrophoresis, electro elution, 2D-PAGE and LC-MS/MS; as well the digested peptides sequence was compared with NCBI database. The result showed a 43% coverage with major royal jelly protein 1 (MRJP-1), well known as a neutraceutical protein in royal jelly. In addition, compared with the result of several references of amino acid sequences of royalactin, we considered that the 57 kDa protein of royal jelly is royalactin. The lyophilized royal jelly and raw material samples were stored at -20, 4, 25 and 37℃ for 4 weeks, respectively. As compared with electrophoresis and densitometer methods, the result showed that the target protein in raw material gradually disappeared as storage temperature and time increased while the target molecule in lyophilized group remained consistent. Adding fermented goat milk extract could have less browning tendencies, much better powder shape, and more protection on royalactin. In conclusion, the 57 kDa protein could be a family of MRJP-1, and consider as royalactin. Adding the fermented goat milk extract can improve storage stability of lyophilized royal jelly. In future, the production of antibody for royalactin can be developed a faster and easier method to evaluate the freshness of royal jelly products.
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