| Using Shatian pomelo from Mei county in Guangdong as materials, the low juice yield and fierce bitter taste during the juice processing were investigated with the advanced modern juice processing technology; and a workshop with annual processing capacity of 2500 t shatian polemo was designed.1. The enzymolysis conditions (temperature, time and the amount of pectinase) were discussed. The results showed that the juice yield rate could reach up to 80% at least by the optimum conditions: temperature, 40-45℃; time, 3 h; amount of pectinase, 75-100 mg/L. After enzymolysis processing, the soluble solids concentration (SSC) of the berry increased by 0.6°Brix, the juice yield increased by 18.2% and the reduction sugar content increased from 9.4 g/L to 10.3 g/L; the viscosity had a significant reduction from 30 mPa·s to 2 mPa·s; the loss rate of V_C was 28.2% and the transparency was greatly improved; however, the juice total acid (TA) and pH changed a bit.2. The variation of bitter taste in the pomelo juice with time, temperature and pH was qualitatively studied by sensory evaluation; and the debittering effects of different methods were also compared. The results showed that bitter taste in pomelo juice increased with time, temperature had a role in promoting transformation of bitterness, and pH led to the color changes. The adsorption of active carbon and LX-900 resins got higher sensory scores, D101 resins play a part role on the decrease of bitter taste but the debittering effects ofβ-cyclodextrin embedding, PVPP adsorption, the enzymatic of nariginase, and ultrafiltration were not obvious.3. Static adsorption and elution performance of resins (D101 resin,AB-8 resin,DM130 resin,D4020 resin,LX-900 resin,ZGA451FD resin) on narigin (the bitterness) in pomelo juice were studied; then D101 resin was chosen to study the dynamic adsorption and elution technological conditions and regeneration stability; finally, the changes in typical properties of pomelo juice before and after D101 resin adsorption were compared. The result of static test showed that narigin, a dihydrochalcone, was easily adsorbed by macroporous absorption resin with non-polar or weak polar and thus the juice was debitterized. In the dynamic test, the effects the height/diameter ratio of D101 resin column, feed flow velocity, pH value of pomelo juice on the adorption of narigin and the effects of the eluent concertration and flow velocity on narigin recovery were studied. The results showed that when the narigin concertration in polemo juice was reduced to 300.0 mg/L, the processing capacity of resin column was about 62BV and the adorption could reach up to 53.8 mg/mL with the condition (height/diameter ratio of D101 resin column (Φ25), 6∶1; feed flow velocity, 14mL/min; pH value of pomelo juice, 3.5). After 9 BV 50% (v/v) ethanol solution passed through the resin column, the column was recovered. In the regeneration stability test, D101 resins had good mechanical resistance, stable adsorption properties, long life cycle and was easily renewable, which was greatly suitable for industrial production. The results of changes in typic properties of pomelo juice showed that D101 resin adsorption can resolve the problem of fierce bitter taste and had little impact on other ingredients.4. A workshop with annual processing capacity of 2500 t Shatian polemo was designed. During the design, a detailed demonstration of process was conducted; after that, material balance, equipment selection, estimation of water, electricity and gas consumption, staffing, the final estimate of the investment and cost were done. The results showed that the total investment of this project is about 23.19 million, annual profit is 9.68 million, and the estimated payback period is approximately 2.4 years. |
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