Study On Fresh-Keeping Packaging Method Of Pinus Koraiensis

The pine nut, as a kind of green organic health food, is more and more warmly welcomed by consumers,not only in the domestic market, but also in the market of Japan and European. At present, the pine nut is supplied in the healthy food monopolized shop and big supermarket in Japan and the wholesale price is 2300 Japanese yen per kilogram (about 20 dollars with first class quality).However, in our country the pine nut still has some problems in producing, storing and processing etc. Such problems above make a bad influence on the domestic export of pine nut and destroy the prestige of it in the international market. The main reason is that the producing region of the pine nut in our country lacks the refrigerating equipment so the pine nut is stored under the normal atmospheric temperature condition more after being reaped. Therefore, the quality will inevitably be influenced as time goes by, thus make the stock of the first class product unable to meet the client's requirement.This thesis aims at exploring the storage techniques for red pine nut, through vacuum packaging and modified atmosphere packaging (MAP) two methodsFirst of all, the experiment divides the red pine nut into two parts:a part is the pine nut without red clothing through 90 temperature and the other part is the untreated pine nut with red clothing. Then the experiment carries on the pretreatment with different vacuum degrees and different atmosphere of the component to two kinds of red pine nut with the air separately, then putting it at ambient temperature. A substandard product quality index is carried on every 45d each time. With constant increase of storing time, a changing regularity of the acid value, saponification value, oxidizing value, etc of the pine nut can be obtained at different vacuum degree conditions and under different MAP conditions.The result of experiment is that the effect of preservation of red pine nut in high suction and high concentration of N2 is better than any other conditions. The red pine nut, with the above two mentioned kinds of packing manner of fresh-keeping packaging, its total fat content is reduced, while its acid value, saponification value and over oxidizing value have rising in various degree after the 6 months storage at normal temperature. In general, the quality of the red pine nut is not destroyed. The techniques defer the freshness period of the red pine nut and achieve the freshness effect.