Optimisation of processing variables in the preparation of sweet potato chips using response surface methodology

Models capable of predicting the product quality of sweet potato chips have been developed using response surface methodology and used to determine the optimum processing conditions. Moisture loss, oil uptake, crispness (measured using a bending-snapping test in the TA.XT2 Texture Analyser), and sensory attributes such as colour, flavour, and texture were used to assess the product quality in the preparation of sweet potato chips. The optimum conditions which were attained for maximum moisture loss (11.65% on wet basis), minimum oil uptake (2.57%), crispness (794.37 g), colour score (7), flavour score (7) and texture score (7) were: frying temperature, 174.7 °C; salt concentration, 0.45%; citric acid concentration, 0.37%; potassium metabisulphite concentration, 0.65%; and frying time, 26 s.     

Optimisation of enzymatic liquefaction of mango pulp by response surface methodology

 Enzymatic liquefaction of the Neelam variety of mango pulp has been optimised by response surface methodology. The effect of enzyme concentration and incubation time and their complex interaction on juice yield, clarity of the juice, alcohol-insoluble solids and viscosity of the mango pulp have been studied using a central composite rotatable design of experiments. The results showed that at the optimum condition (enzyme concentration and incubation time of 0.14% and 46.67 min, respectively) the yield was ≥64%, clarity ≥71%, alcohol-insoluble solids ≤2.0% and viscosity ≤1850 cP. Received: 28 May 1998     

响应面法优化花椒香气成分的HS-SPME萃取条件的研究

为了优化花椒香气成分HS-SPME萃取,在单因素实验的基础上,利用Box-Benhnken的中心组合实验设计原理,以提取物质的质(色)谱图总峰面积为考察指标,对萃取温度、萃取时间、原料用量进行3因素3水平响应面分析。结果表明,萃取温度对总峰面积有显著影响,萃取时间和原料用量对其影响不显著;萃取时间和原料用量的交互作用显著,其它交互作用均不显著;得到萃取花椒香气成分最佳的工艺条件为:萃取温度55.97℃,萃取时间30.73min,原料用量3.15g,在此条件下,香气成分总峰面积为2.21101×109。     

响应面分析法优化黄酒风味物质的检测条件

用顶空固相微萃取,结合气相-质谱联用技术分析了黄酒中的挥发性风味成分。通过对萃取条件(萃取头、萃取温度、萃取时间和解吸时间)的单因素实验以及响应面设计的研究确定了检测3年陈黄酒风味物质的最佳条件,当使用Polyacrylate萃取头,萃取温度为45℃,萃取平衡时间为40min,解吸时间为4min时出峰个数为48个,出峰面积为5.15×104。通过最优条件下的GS-MS对3年陈黄酒中风味物质主要成分进行定性,主要的醇类物质有:乙醇、正丁醇、异丁醇、苯乙醇、丙醇等;主要的酸类物质有:乙酸、己酸、异丁酸等;主要的醛类物质有:苯甲醛、糠醛等;主要的酯类物质有:乙酸乙酯、丁酸乙酯、己酸乙酯;主要的酮类物质有:苯乙酮、甲基壬基酮。     

Optimisation of fermentation conditions for mango (Mangifera indica L.) wine production by employing response surface methodology

Response surface methodology (RSM) was employed for the simultaneous analysis of fermentation conditions of temperature, pH and inoculum size on chemical characteristics such as ethanol, glycerol and volatile acidity, produced during mango wine production by Saccharomyces cerevisiae ( var. bayanus ). The experiments were carried out according to the central composite design to establish the optimum conditions for improving the quality of mango wine. The predicted values for optimisation process conditions were in good agreement with experimental data. The results showed that a satisfactory production of ethanol from the mango juice could be achieved reaching up to 10% (v/v), glycerol concentration is increased to 6.94 g L⁻¹ and volatile acidity is minimised to 0.29 g L⁻¹ at optimised fermentation conditions of temperature 22.5 °C, pH 3.8 and inoculum size 11.9%. Verification of the model indicated no difference between predicted and observed values. Sensory evaluation studies shown overall acceptance of mango wine with good quality.     

响应曲面法优化鸭肫酶解制备抗氧化肽工艺

在单因素实验基础上应用响应面法对鸭肫抗氧化肽制备工艺进行优化。在前期筛选酶解鸭肫的最佳蛋白实验中得到木瓜蛋白酶为酶解鸭肫蛋白的最佳作用酶,优化的鸭肫抗氧化肽最佳工艺条件为:酶解时间4.0 h、加酶量0.5%、酶解温度55℃、料液比1∶3 g/m L。在此条件下,酶解鸭肫蛋白的水解度可达28.30%,DPPH·清除率为75.10%。结果表明该鸭肫抗氧化肽工艺制备可行,鸭肫蛋白水解度与DPPH自由基清除能力之间不存在相关性。      

Optimisation of cake fat quantity and composition using response surface methodology

The influence of fat quantity and composition on the characteristics of a chemically leavened baked product was investigated, applying a central composite design combined with response surface methodology. Fats were blends of palm oil and palm olein with different slip melting points (from 36.3 to 11.3 °C, in dependence of increasing olein content). Fat content (from 5.3% to 30.7% on batter) and percentage of olein in the fat blend (from 42.7% to 92.2%) were varied. The increase of fat quantity enhanced cake softness, while lowering the volume; higher olein contents also decreased cake firmness. An optimised formulation containing 19.7% fat with 92% olein in the fat blend and showing good structural properties, comparable to those of a 18% butter reference cake, was identified. The optimised and the butter cake showed specific volume of 2.25 and 2.23 cm³ g^?1, respectively, and load at 25% strain of 7.68 and 5.63 N. These results demonstrated the possibility to replace butter with a liquid vegetable fat blend, thus increasing unsaturated fat content and reducing total cholesterol in the product.     

Optimisation of osmotic dehydration process of guavas by response surface methodology and desirability function

Response surface methodology was used to assess the effects of osmotic solution concentration (40–60°Brix), process temperature (20–40 °C) and vacuum pulse application time (0–20 min) at 100 mbar on water loss (WL), weight reduction (WR), solid gain (SG), water activity (a_w), colour parameters and mechanical properties of guava slices. Optimal process conditions were determined through the desirability function approach and quality characteristics of osmotically dehydrated guavas were analysed. Only models obtained for WL, WR and a_w were suitable to describe the experimental data. The desirability function showed that optimal conditions for osmotic dehydration of guavas were: osmotic solution concentration at 60°Brix, process temperature at 32 °C and 20 min of vacuum pulse application. Under optimal conditions, colour and mechanical properties of treated guavas were similar to fresh fruit, presenting WL of 29.01 g/100 g, WR of 25.91 g/100 g, SG of 3.10 g/100 g and a_w of 0.979.     

响应面法优化麦汁糖化工艺条件

以大麦芽、小麦芽为原料,麦汁浸出物收得率为评价指标,在单因素试验基础上,利用响应面法对麦汁糖化工艺进行优化研究。结果表明,最佳的糖化工艺为小麦芽添加量为42.0%,水料比为4∶1（mL∶g）,37 ℃投料保温10 min,52 ℃糖化保温45 min,65 ℃糖化保温68 min,78 ℃保温10 min。在此优化糖化工艺条件下,测得麦汁浸出物得率为79.63%,比未优化前提高8.2%。麦汁糖化液中α-氨基酸态氮含量为272.01 mg/L,还原糖含量为9.14 g/100 mL,可溶性氮含量为1.41 g/L。     

Optimisation of extraction conditions for recovering carotenoids and antioxidant capacity from Gac peel using response surface methodology

The peel of Gac fruit is regarded as waste product in the processing of Gac although it contains high level of carotenoids and possesses a significant antioxidant capacity. This study optimised the extraction yields of carotenoids and antioxidant capacity from Gac peel. Different organic solvents were examined to determine the most suitable solvent for the extraction. The extraction conditions including time, temperature and solvent–solid ratio were then optimised for maximising extraction yields of carotenoids and antioxidant capacity from Gac peel using response surface methodology. Ethyl acetate was identified as the most suitable solvent. The optimal extraction time, temperature and solvent–solid ratio were 150 min, 40.7 °C and 80 mL g^?1, respectively. The carotenoid extraction yield and the antioxidant capacity extraction yield were 271 mg/100 g DW and 737 μm TE/100 g DW, respectively. Thus, the extraction using ethyl acetate with the ratio of 80:1 (mL solvent per g Gac peel) for 150 min at 40.7 °C is suggested for recovering carotenoids and antioxidant capacity from Gac peel.     

响应面法优化人参糖蛋白制备工艺

目的:优化人参糖蛋白的制备工艺.方法:利用Box-Behnken响应面法分析提取时间、提取次数、料液比、乙醇体积分数对人参糖蛋白的影响.结果:最优人参糖蛋白制备工艺为提取时间1.5 h、提取次数3次、料液比(m人参粗粉∶V蒸馏水)1.0∶ 15.4(g/mL)、乙醇体积分数72％,该条件下人参糖蛋白质量分数为24.14...     

响应面法优化抗性糊精制备工艺

以玉米淀粉为原料,在单因素试验的基础上,利用响应面试验设计优化酶解法制备抗性糊精的工艺条件,研究α-淀粉酶作用温度、添加量和转苷酶作用温度、添加量及其交互作用对抗性糊精产率的影响。结果表明,最佳酶解工艺为α-淀粉酶作用温度94 ℃,α-淀粉酶添加量0.4%,转苷酶作用温度56 ℃,转苷酶添加量0.3%。在此优化工艺条件下,抗性糊精产率为82.56%,与预测值相对误差为1.46%,表明运用响应面试验法优化得到的该模型有一定的实践指导意义。     

响应面法优化乳铁蛋白提取工艺的研究

干酪乳清经过过滤、超滤预处理,利用阳离子交换层析分离纯化得到乳铁蛋白。用SDS-PAGE电泳、考马斯亮蓝法对样品进行检测。利用响应面法对乳铁蛋白的提取工艺进行优化。结果表明:提取得到的乳铁蛋白纯度约为90%,相对分子质量为80000u。在洗脱剂pH6.83、流速为0.78BV/h、起始洗脱剂为0.0085mol/L磷酸缓冲溶液条件下,蛋白提取量达到最大19.94mg/L乳清。     

Optimisation of the extraction conditions of natural colourant carthamin from safflower (Carthamus tinctorius L.) by response surface methodology

Alkali‐solution and acid‐isolation method (ASAI) and aqueous two‐phase system separation method (ATSS) have been reported to extract natural colourant carthamin from Carthamus tinctorius. In this study, these two methods were compared based on the optimisation results of extraction conditions by response surface methodology. In ASAI, the maximum extraction yield reached 0.779% at pH value of potassium carbonate solution of 11.16, ratio of potassium carbonate solution to raw material of fifteen and extraction time of 18 min, while 2.652% was achieved with concentration of acetone of 58%, ratio of acetone solution to raw material of twenty‐three and extraction time of 41 min in ATSS. From the point of view of extraction yield, ATSS had more superiority than ASAI. However, more pure carthamin was provided in ASAI according to HPLC assay. The obtained results in our experiments could be utilised for further researches of carthamin.     

Optimisation of sourdough bread incorporation into wheat bread by response surface methodology: Bioactive and nutritional properties

The optimisation of the quantity of sourdough (A) prepared with two different fermentation methods, [spontaneous fermentation (F1) vs. starter of lactic acid bacteria‐added fermentation (F2)], instant active dry yeast (B) and wheat bran (C) for a nutritionally improved bread formulation has been studied by evaluating the bioavailability and bioactive properties. The bread produced according to the optimised formula and fermentation types of F1 (OB_F1) and F2 (OB_F2) was compared with control bread (CB). The optimised levels for F1 were 11.45% for sourdough, 1.10% for dry yeast and 1.58% for wheat bran and for F2 6.99% for sourdough, 1.02% for dry yeast and 38.84% for wheat bran. The addition of sourdough significantly (P < 0.05) affected antioxidant activity, total phenolic content, in vitro ash and protein digestibility, and enzyme resistance starch contents of bread. The F1 fermentation method was found to be more effective in terms of bread properties examined.     

响应曲面法优化rmHSA-GCSF的发酵工艺

采用Plackett-Burman设计法对影响巴斯德毕赤酵母(Pichia pastoris)表达重组人血清白蛋白-粒细胞集落刺激因子突变体(rmHSA-GCSF)的主要参数进行了摇瓶试验,选取到3种显著效应的因素:诱导pH、甲醇添加浓度和诱导时间。再利用响应曲面法(Response surface method)对这3种因素进行进一步研究,得到最佳培养条件:甲醇诱导浓度为2.45%,诱导pH为5.54,诱导时间为66.4 h。采用此优化参数,rm HSA-GCSF表达量的最大预测值达157.5 mg/L。此后,根据优化的培养条件,进行150 L发酵罐放大试验,rm HSA-GCSF表达量达到600 mg/L左右,成功实现rm HSA-GCSF的高效表达。     

响应面分析法优化糟醉带鱼的糟醉工艺

采用响应面分析法对糟醉带鱼的糟醉工艺进行优化。在单因素实验基础上,根据中心组合实验设计原理,采用三因素三水平的响应面分析法,以糟醉带鱼的感官评分为响应值进行回归分析。结果表明,糟醉带鱼糟醉的适宜工艺条件为加盐量4.7%,加酒量7.1%,糟鱼比1:2.2,在此条件下制得的糟醉带鱼感官评分最优,达到84.5分,与模型预测值基本相符。      

响应面分析法优化糟醉带鱼的糟醉工艺

采用响应面分析法对糟醉带鱼的糟醉工艺进行优化.在单因素实验基础上,根据中心组合实验设计原理,采用三因素三水平的响应面分析法,以糟醉带鱼的感官评分为响应值进行回归分析.结果表明,糟醉带鱼糟醉的适宜工艺条件为加盐量4.7％,加酒量7.1％,糟鱼比1∶2.2,在此条件下制得的糟醉带鱼感官评分最优,达到84.5分,与模型预测值基本相符.