Optimum Research On Decolouring Technology And Spray Drying Technology Of Soybean Peptide

Using soybean, soybean meal or soybean protein as raw material to product soybean peptide by enzymatic or by microbial fermentation, the distribution of molecular weight always below in10,000Da. Compare with soy protein, soybean peptide has better physicochemical properties and special physiological functions. Application prospects are bright in areas such as food, medicine, light industry.In this study, using high-quality soybean meal as raw material, we acquire soybean peptide hydrolysate by hydrolysis fermented soybean meal. We obtain soybean polypeptide solution which have better sensory and its molecular weight relative concentration. On the basis, we add active carbon or macroporous resin to decolorize and obtain soybean peptides which have stable property. It always be easy to store.The decoloring rate as indicator, we choose the best optimum decoloring agent (activated carbon powder) from clay, diatomite, activated carbon powder and active carbon granule. We selected the best optimal type (AB-8resin) from D101resin, DM-130resin, AB-8resin. The decoloring rate and the loss rate of peptide as indicators, we tested the effect of concentration of activated carbon, decoloring time, temperature and pH to the decoloration of soybean peptide solution; in addition, we optimized these contributing factors through orthogonal experiment. The data demonstrated that the optimal decoloring condition to soybean peptide was the addition of2.0%(w/w) activated carbon in decoloring solution (pH8.0) and incubation at55℃for50min. And then, the decoloring rate was tested up to57.13%and loss rate of peptide was11.37%under this condition. In this study, we further decolorized the treated soybean peptide solution with AB-8resin. After the treatment with AB-8resin (0.5g/ml) for9h, the decoloring rate was tested up to57.99%and loss rate of peptide was16.19%under this condition. After the treatment with activated carbon and AB-8resin step-by-step, total decoloring rate of soybean peptide solution reached81.97%and the total loss rate of peptide was26.74%. The adsorption rate and desorption rate as indicators, we tested the effect of concentration of regeneration solution (HCl, NaOH), flow, the volume ratio of regeneration solution and macroporous resin, regeneration time to regeneration of macroporous resin. The data demonstrated that the best regeneration conditions to macroporous resin was the volume ratio of regeneration solution (HC1or NaOH:3%～5%) and macroporous resin (2-3:1) at the rate (4-6m/h) in natural solution and room temperature for20～24h.Sensory traits and the content of protein as indicators, the data of single factor experiment demonstrated that the best spray drying condition was concentration of feed liquid (200%) at the rate (400ml/h) at45℃through dryer which we seted air inlet temperature150℃and air outlet temperature60℃.The data demonstrated that molecular weight of soybean peptides and peptide powder hydrolysate solution showed little difference. The distribution of molecular weight of product below in10,000Da was80%.