饮料型马铃薯酸奶的研究

本文研究了马铃薯酸奶的加工工艺和最佳配方。实验结果表明：热烫时间为３ｍｉｎ，质后颗粒直径≤３μｍ；最佳发酵工艺为：接种量２－４％，发酵时间４ｈ，培养温度４１－４３℃；最佳配方条件为：马铃薯２０－３０％，牛乳１０－１５％，蔗糖１．５－２％，酸性ＣＭＣ０．２％，魔芋精粉０．２％。     

甘薯叶片可溶性蛋白提取方法探索及其成分分析

探索了甘著叶片可溶性蛋白质的浸提方法,确定了蛋白质的沉淀方法,并分析了叶片可溶性蛋白粉中粗蛋白含量、粗纤维、粗脂肪和蛋白质中的氨基酸组成。结果表明,甘薯叶片主要含有一种分子量为53000Da的可溶性蛋白质,用pH为6．5～7．5的1％亚硫酸氢钠溶液浸提甘薯叶片粉末可较好地提取甘薯叶片中的可溶性蛋白质。经浸提、沉淀、透析、冻干处理获得的台农叶片蛋白粉中含有62．6％粗蛋白、0．18％粗纤维和0．51％粗脂肪。台农叶片可溶性蛋白质含有各种人体所需要的氨基酸,主要氨基酸是赖氨酸(99．88mg/g蛋白质)、亮氨酸(12026mg/g蛋白质)和天门冬氨酸(140 74mg/g蛋白质),并且必需氨基酸含量高于非必需氨基酸的含量,其比值为1．04,第一限制性氨基酸为色氨酸,氨基酸分数为75．9。     

应用均匀设计和响应面分析优化马铃薯渣发酵蛋白饲料的工艺

研究以马铃薯渣为主要原料,通过均匀设计得到发酵工艺对发酵产物中粗蛋白质和真蛋白质含量影响较大的3个因素及取值范围;再通过响应面分析对马铃薯渣蛋白饲料的发酵工艺进行优化,得出最佳的发酵工艺为:培养基水分150％,糖化时间30 min;糖化温度30℃,发酵时间42 h,发酵温度30℃,酶添加量4％.发酵产品中粗蛋白质、真蛋白质质量分数较发酵前分别提高180.28％、156.19％.     

红薯叶苋菜复合饮料的研究

通过对红薯叶和苋菜原料配比、浸提条件、护色、调配等的研究，选择出最佳实验配比方案；红薯叶：苋菜为4：3，红薯叶浸提时间为3h，苋菜浸提时间为2h，柠檬酸为0．01％，蔗糖为7．0％，抗异坏血酸钠为0.2％。最终生产出了色、香、味俱佳的具有保健功能的天然红薯叶苋菜复合饮料。     

The Effect of Antibrowning Agents on Inhibition of Potato Browning,Volatile Organic Compound Profile,and Microbial Inhibition

Abstract: Burbank and Norkotah potato slices were dipped into 3% sodium acid sulfate (SAS), citric acid (CA), sodium erythorbate (SE), malic acid (MA), sodium acid pyrophosphate (SAPP), or a combination of SAS‐CA‐SE. Browning by polyphenol oxidase (PPO) obtained from potato extract with 0.04 to 0.016 g/mL of antibrowning solutions at pH 2.0 to 6.9 were measured by UV‐Vis spectroscopy. The color of slices dipped in antibrowning solutions at pHs 2 to 7 and stored at 4 °C for 15 d was measured every 5 d by colorimeter. Headspace analysis of volatiles in raw and cooked potato samples was performed by selected ion flow tube mass spectrometer (SIFT‐MS) and soft independent modelling by class analogy (SIMCA) analysis of the calculated odor activity values (OAV) determined interclass distances. Microbial growth was measured at 15 d. At unadjusted pHs (1.1 to 7.1), the PPO browning of the control and samples with SAPP was not significantly different, SAS, CA, and MA produced some inhibition and SE and SAS‐CA‐SE prevented browning. At pH 5 to 7, only SE and SAS‐CA‐SE were effective browning inhibitors. Based on the color of potato slices, SE was the most effective at pH 2 to 7, but SAS was most effective at unadjusted pH. Cooking increased volatile levels in the treated potatoes and decreased differences between volatile profiles. Differences between cooked samples may not be noticeable by the consumer because volatiles with high discriminating powers have low OAVs. SAS, CA, and SAS‐CA‐SE treatments inhibited microbial growth but SAPP, control, and SE did not, most likely due to pH. Practical Application: Antibrowning agents inhibit polyphenol oxidase, increasing shelf life and consumer acceptability of processed raw potato products by preserving the color. Their effectiveness was shown to be mainly due to a pH effect, except SE, which was not pH dependent. MA, CA, and SAS‐CA‐SE are better acidulants for inhibition of color change as well as growth of spoilage bacteria, yeast, and mold than SAPP, the industry standard.     

Flow behaviour of carrot puree: modelling the influence of time,temperature and potato flakes addition

Rheological properties of carrot puree were investigated in the 1–1000 s^?1 shear rate range with the objective of modelling the influence of time, temperature and addition of potato flakes on the flow behaviour. Carrot puree exhibited a shear‐thinning behaviour that was well described by the Ostwald‐de Waele (Power Law) model with a flow behaviour index of 0.34 (±0.02) at 20 °C. The time‐dependent behaviour was characterised by a second‐order Structural Kinetic Model. The decay of the structural parameter with time was found to be independent of shear rate. The Arrhenius model was used to explain the effect of temperature in the range from 4 to 60 °C. The dry matter was increased by adding potato flakes (0–5%). A power law model (for the concentration) and the Arrhenius relationship (for the temperature) were combined to simultaneously describe the effects of temperature and concentration. This study provides essential data for equipment and process design.     

N,N′-alkylated Imidazolium-Derivatives Act as Quorum-Sensing Inhibitors Targeting the Pectobacterium atrosepticum-Induced Symptoms on Potato Tubers

Bacteria belonging to the Pectobacterium genus are the causative agents of the blackleg and soft-rot diseases that affect potato plants and tubers worldwide. In Pectobacterium, the expression of the virulence genes is controlled by quorum-sensing (QS) and N-acylhomoserine lactones (AHLs). In this work, we screened a chemical library of QS-inhibitors (QSIs) and AHL-analogs to find novel QSIs targeting the virulence of Pectobacterium. Four N,N′-bisalkylated imidazolium salts were identified as QSIs; they were active at the μM range. In potato tuber assays, two of them were able to decrease the severity of the symptoms provoked by P. atrosepticum. This work extends the range of the QSIs acting on the Pectobacterium-induced soft-rot disease.     

薯干原料粗淀粉含量的快速测定

探讨了用１∶４硫酸溶液水解薯干淀粉的快速测定法，并与传统法比较。认为快速法作为指导生产实际的测定方法，具有一定的应用价值。