Preservation Blueberries And Wine Technology

Blueberries belong to the fledgling country sunrise industry, which has a high nutritional health function, known as the "king of berries"; but because blueberries are berry intolerance storage in postharvest vulnerable to corruption and lost economic value. In this paper, blueberries as experimental materials, through processing of chitosan coating at low temperatures under normal temperature conditions and storability; pair of blueberry wine fermentation process optimization; research on its basis blueberry wine during fermentation of organic acids and aroma over time changes. Aims to explore fresh blueberries and deep processing technology for the healthy development of blueberry industry provide a theoretical basis. The main results are as follows.1. preservation blueberries experiment (room temperature20℃, low temperature2℃):0.5%chitosan soak" round blue" blueberry fruit3min, by measuring the blueberries during storage at room temperature and low temperature sensory and physiological and biochemical indexes, discover chitosan on blueberries preservation effect. The results showed that: Chitosan can maintain blueberry fruit sensory quality, hardness, reduced weight loss and decay rate, significantly inhibited the accumulation of MDA fruit, slightly reduced anthocyanin content, total phenolic content and promote the increase of relative conductivity. Delaying fruit TSS levels rise at room temperature, to prevent post-TSS content decreased; improve low temperature TSS content of fruit to maintain normal temperature TA content; reduce low temperature TA fruit content. Flavonoids reduce room temperature, low temperature, improve fruit flavonoids. Promote early storage at room temperature PPO activity, reduce late storage PPO activity; early storage at low temperatures inhibits the activity of PPO, PPO activity to promote late storage. Room temperature to reduce fruit PAL activity; low temperatures promote early storage PAL activity, reducing post-PAL activity. Compared with the control, chitosan treatment can significantly prolong the storage period of blueberry fruit.2. blueberry wine fermentation process optimization With frozen blueberries as raw material, through the single factor experiment combining Box-Behnken central composite experimental design and response surface methodology blueberry wine fermentation process, the results showed that: the amount of0.09%of yeast added, fermentation temperature23.8℃, pH3.30, SO2dosage38.7mg/kg,7d fermentation under optimal conditions, after aging alcohol volume fraction obtained11.8%vol, pure flavor and health benefits of blueberries with fermented wine.3. Blueberry wine fermentation process of the evolution of organic acids and aroma. This test uses high-performance liquid chromatography (HPLC) and headspace solid phase microextraction (HS-SPME) combined with mass spectrometry technique (GC-MS) respectively blueberry wine fermentation process organic acids and aroma components analysis, combining threshold Odour activity value relative (ROAV) for evaluation of the contribution of aroma components. The results showed that:the selected HPLC conditions, oxalic acid, tartaric acid, malic acid, lactic acid, citric acid, succinic acid and to separate a good standard curve correlation coefficient was0.9998or more. Blueberry wine fermentation process, lactic acid, acetic acid, malic acid, succinic acid content was increased after the first drop; citric acid and tartaric acid remained relatively stable; oxalic acid first increased and then decreased. After fermentation, a total of56kinds of aroma compounds identified, including21kinds of esters, alcohols,9species acids5species, eight kinds of aldehydes and ketones, olefins12species and two kinds of naphthalene compounds; higher levels of the ester, alcohols, volatile acid and the like; ROAV analysis with a threshold value, the critical blueberry fruit aroma (ROAV≥1) are:ethyl caproate, D-Limonene, ethyl benzoate, decanal, decyl aldehyde, ethyl, twelve ethyl; fermentation process, decanal, ethyl caproate, D-Limonene and ethyl benzoate increased first and then decreased again stabilized; decanal ethyl acrylate and twelve decreased first increased, then leveled off trend.