Improving textural quality in frozen jalapeño pepper by low temperature blanching in calcium chloride solution

The effects of low temperature blanching in calcium chloride solution of jalapeño peppers prior to freezing, on firmness retention, pH, methanol, colour and calcium ions of the product, were evaluated by response surface methodology. Texture, methanol content and pH were affected by all of the variables studied (P = 0.05). The optimum response was obtained at temperatures of 63.3–66 °C, calcium chloride concentrations of 0.17–0.21 m , immersion time of 11.6–14.4 min, with a holding time after blanching of 56.6–66.1 min. Microscopic evaluation of the thawed pepper showed that blanching in CaCl₂ solution provided a protective effect in maintaining cell wall integrity.     

即食栗蘑加工工艺研究

以新鲜栗蘑为原料,利用单因素和正交试验设计方法,研究硬化、漂烫的最佳工艺及拌料的最佳配方。结果表明:最适的硬化条件是在浓度为0.5%氯化钙和0.5%氯化钠的混合溶液中浸泡40 min。最佳漂烫条件是在浓度为0.3%的柠檬酸和0.06%的抗坏血酸混合溶液中漂烫4 min。最佳拌料配方为每100克栗蘑中加入3 g盐,0.7 g糖,3 g辣椒粉。可制得具有栗蘑特有风味,口感脆嫩,营养丰富,方便安全的新型即食栗蘑食品。     

猕猴桃果脯制作工艺优化

本文对猕猴桃果脯制作工艺进行优化,采用单因素实验探究了不同护色剂种类、硬化剂浓度和不同烫漂时间对猕猴桃果脯色度、硬度及总糖含量的影响,并利用Box-Behnken Design中心组实验设计,对渗糖时间、干燥时间和干燥温度进行响应面优化,研究各自变量及其交互作用对猕猴桃果脯总糖含量及感官的影响,并得到二次多项式回归方程的预测模型。结果表明,最佳护色条件为2 g/L的柠檬酸、氯化钠和异抗坏血酸钠的混合液,其体积比例为1:1:1;硬化剂为0.8 g/L氯化钙;烫漂时间为140 s。通过回归分析,果脯制备最优条件为渗糖时间48 min,干燥时间为5 h,干燥温度为80℃。在该条件下,猕猴桃果脯总糖含量与感官评价的实际综合值为75.41,与预测值74.60符合较好。通过研究表明优化猕猴桃果脯生产工艺可明显提升猕猴桃果脯的质量。     

交联体系对海藻酸钠/印度树胶复合膜性能的影响

为探究交联体系对海藻酸钠/印度树胶复合膜性能的影响,本文选取氯化钙-柠檬酸、氯化钙-乳酸、氯化钙-苹果酸三种不同的Ca2+-H+交联体系,以力学性能、水蒸气透过率及水溶性为指标进行评价;同时,利用傅里叶红外光谱(FTIR)、扫描电子显微镜技术(SEM)进行微观结构表征。结果表明,选用氯化钙-柠檬酸交联体系,Ca2+浓度为1.5%,H+浓度为1.0%,交联时间为5 min时,拉伸强度为34.11 MPa,断裂伸长率为15.27%,水蒸气透过率为6.99×10-11 g/(m·s·Pa),水溶性为6.41%,海藻酸钠/印度树胶复合膜综合性能最佳。此外,傅里叶红外光谱和扫描电子显微镜也表明氯化钙-柠檬酸交联体系形成的交联膜微观结构紧密、均匀、交联度高。本研究成功制备了一种新型复合膜,为其在食品包装领域的应用提供理论依据。     

Effects of salt mixtures on Spanish green table olive fermentation performance

This work investigates the effect of sodium, potassium, and calcium chloride salts on the performance of Spanish green table olive fermentation using a simple centroid mixture design. The presence of calcium chloride hindered the diffusion of all sugars and delayed the period required to reach their respective maximum concentrations in brines. Such effects can prevent tumultuous processes and gas pocket spoilage. Acetic acid was present at low concentrations in all treatments but was not generated during fermentation. The production rate of lactic acid was either decreased or delayed by the presence of calcium chloride but adequate final conditions were always reached. The chemometric analysis classified treatments into groups according to the presence of calcium chloride and disclosed a stimulating effect of potassium on lactic acid production. Therefore, these techniques can be a useful tool to investigate olive fermentation performance. According to the results, acceptable Spanish green table olives can be produced using salt mixtures, with the subsequent reduced sodium content in the final products. The results obtained in this study could also be of interest for other fermented vegetables.     

Effect of additives on dough development, gaseous release and bread making properties

The study was carried out to investigate the effect of additives (lactic acid, fat and sodium chloride) and process variables (mixing duration and fermentation temperature) on dough development and gaseous release characteristics measured by Rheofermentometer F₂ and bread volume. H_m (maximum dough height) was most significantly affected by mixing duration and sodium chloride whereas H_m′ was most significantly affected by fermentation temperature and fat levels. Increased levels of fat (%) showed improving effects on dough development and bread volume, however fat addition did not counteract the adverse affects of over mixing and addition of lactic acid and sodium chloride at higher levels. The models computed had R² value ranged between 91.5–98.7%, indicating they are appropriate and can be a useful tool to predict the effect of addition of lactic acid. fat and sodium chloride and process variables mixing duration and fermentation temperature on dough development, gaseous release and bread volume.     

低糖雪莲薯果脯真空渗糖工艺条件的优化

研究低糖雪莲薯果脯的加工工艺条件,对护色、漂烫和硬化等渗糖前预处理过程进行研究,得出最佳条件:用0.4%浓度的柠檬酸溶液对原料护色,沸水漂烫10min,0.5%浓度氯化钙溶液对原料进行硬化2 h.采用真空渗糖的方法对原料糖渍处理,并对真空渗糖温度、渗糖时间、柠檬酸用量和糖液浓度等因素设计正交试验,得出最佳工艺条件:温度35℃、时间120min、柠檬酸0.20%及蔗糖45%.     

Modeling of pre-treatment protocols for frozen pineapple slices

Optimization of pretreatments - blanching and additives was carried out for frozen pineapple slices using response surface methodology (RSM). The effect of pre-treatments viz. blanching medium (10-20° Brix sucrose solution), calcium chloride (1000-2000 ppm) and ascorbic acid (200-400 ppm) was studied on hardness (N), colour (L*), syneresis (%) and sensory attributes (colour, aroma, taste, overall acceptability) of the frozen slices after thawing. A Central Composite Rotatable Design (CCRD) was used with six experiments at the central point. The data obtained were analysed employing multiple regression technique to generate suitable mathematical models. Quadratic models were found to fit well (R², 96.72-99.99%) in describing the effect of variables on the responses studied. Optimization of the pretreatments was carried out by maximizing the hardness, L* and sensory responses while keeping the syneresis at minimum level. Compromised optimum values for blanching medium, calcium chloride and ascorbic acid levels were found to be 17° Brix, 1493 ppm and 300 ppm; respectively. The experimental and predicted values showed high correlation coefficients. The optimized pretreatment was found to be helpful in maintaining the quality of frozen pineapple slices in terms of texture, colour and syneresis.     

Measurement and targeting of thermophysical properties of carrot and meat based alginate particles for thermal processing applications

The objective of the study was to investigate the thermo-physical properties of meat and carrot based alginate particles as influenced by the formulation variables. A response surface methodology (RSM) was used to study the effect of sodium alginate concentration, calcium chloride concentration and dipping time in the calcium chloride solution, at five levels each, on the thermo-physical properties of the fabricated particles (9 mm in diameter and 9 mm in height). Density was similar for all conditions. Increasing sodium alginate concentration resulted in a significant decrease in the heat capacity and thermal conductivity values. These changes were primarily attributed to the lowering of moisture content of the particles resulting from the treatment. Using RSM, optimum conditions for fabricating particles having similar thermo-physical properties to real foods were obtained as 5.3% and 4.9% sodium alginate, 2.2% calcium chloride and 14.2 and 36.0 h immersion in the calcium chloride solution for meat and carrot alginate particles, respectively.     

Effects of pretreatments on the texture and ascorbic acid content of frozen plantain pulp (Musa paradisiaca)

The effects of water blanching, steam blanching, microwave blanching and calcium chloride pretreatment on the physical and sensory properties and ascorbic acid content of frozen plantain (Musa paradisiaca L) pulp was studied. After freezing and reheating, the microwave treatment produced a similar texture to that obtained with calcium chloride treatment, and both were significantly (P<0.01) better than conventional water or steam blanching. Microwave treatment improved retention of ascorbic acid.     

不同预处理方式对热风干燥黄花菜褐变及干燥特性的影响

本实验探究不同护色液（0.1 g/100 mL柠檬酸、0.2 g/100 mL柠檬酸、0.2 g/100 mL碳酸氢钠、1.0 g/100 mL氯化钠溶液,浸泡45 min）对烫漂（蒸汽和热水,处理2 min）处理后黄花菜成品褐变抑制及干燥特性的影响,对其干制品外观色泽、营养成分和微观结构进行表征,同时采用傅里叶变换红外光谱法比较不同预处理对其结构的影响,并通过主成分分析获取具有较高商品价值的黄花菜干燥预处理条件。结果表明,抑制褐变效果方面：蒸汽烫漂>热水烫漂;0.2 g/100 mL柠檬酸溶液>0.1 g/100 mL柠檬酸溶液>1.0 g/100 mL氯化钠溶液>0.2 g/100 mL碳酸氢钠溶液。干燥处理效果方面：采用0.2 g/100 mL柠檬酸溶液进行护色处理的黄花菜干燥速率最快且复水效果较好;综合考量,以蒸汽烫漂（2 min）+0.2 g/100 mL柠檬酸溶液浸泡（45 min）条件进行预处理后,黄花菜干制品的外观色泽、黄酮与多酚含量及微观结构等品质较佳。经主成分分析可知,多酚含量、5-羟甲基糠醛含量与色差、褐变度高度相关,咀嚼性与硬度相关性最高...     

Effect of Total and Partial Substitution of Sodium Chloride on the Quality of Cheddar Cheese

Cheddar cheese was manufactured to give 1.6% residual sodium chloride or equivalent amounts (ionic strength basis) of magnesium chloride, calcium chloride, potassium chloride, or 1:1 mixtures of sodium chloride and the chloride salt of magnesium, calcium, or potassium from two split batches of curd. Sensory evaluation after 4 mo ripening at 4°C showed that cheese salted solely with magnesium chloride, calcium chloride, or potassium chloride was extremely bitter and totally unacceptable. There was extensive lipolysis (as measured by free fatty acid development) in the cheese salted with magnesium chloride, calcium chloride, or potassium chloride. Proteolysis was highest in the cheese salted with calcium chloride and magnesium chloride. These cheese gave the lowest Instron values for firmness, hardness, and cuttability. Extensive proteolysis in these cheese may be partly due to the low salt in moisture. Taste panel scores for flavor and texture of the sodium chloride/calcium chloride and sodium chloride/magnesium chloride salted cheese were significantly lower than the scores for the control cheese. Scores for flavor and texture of the potassium chloride/sodium chloride salted cheese were not significantly different from scores of the control cheese.     

EFFECT of LOW TEMPERATURE BLANCHING, CYSTEINE-HCi, N-ACETYL-L-CYSTEINE, Na METABISULPHITE and DRYING TEMPERATURES ON the FIRMNESS and NUTRIENT CONTENT of DRIED CARROTS

Low temperature long time (LTLT) blanching (70C for 20 min) together with calcium treatment can be used to significantly improve the texture of rehydrated dried carrots when compared to high temperature short time (HTST) blanching (100C for 3 min). LTLT blanching allows pectin methyl esterase to deesterify pectin which can then react with calcium to form salt bridges. 0.3% L-cysteine-HCl was found to be most effective in preventing ascorbic acid loss and obtaining a product with the highest rehydration ability, compared to pretreatments with 0.3% N-acetyl-L-cysteine and 0.1% sodium metabisulphite. On the other hand 0.1% sodium metabisulphite was most effective in preserving the carotenoids content of dried carrots. Ascorbic acid and rehydration ability were more adversely affected by long drying time than high drying temperature, while carotenoids were more sensitive to high drying temperature than drying time. Hence, 60C drying temperature was good for ascorbic acid and rehydration ability, while 40C drying temperature was good for carotenoid and color of dried carrots.     

Effect of sodium gluconate on the solubility of calcium lactate

Calcium and lactate are present in excess of their solubility in Cheddar cheese. Consequently, calcium lactate crystals (CLC) are a common defect in Cheddar cheese. A novel approach for preventing CLC is the addition of sodium gluconate. Sodium gluconate has the potential to increase the solubility of calcium and lactate by forming soluble complexes with calcium and lactate ions, and preventing them from being available for the formation of CLC. The objective of this study was to determine if sodium gluconate could increase the solubility of calcium lactate (CaL₂). Seven CaL₂ solutions (5.31% wt/wt) with 7 levels of sodium gluconate (0, 0.5, 1, 1.5, 2, 3, and 4% wt/wt) were made in triplicate. Solutions were stored at 7°C for 21 d, and were visually inspected for CLC formation. Subsequently, they were filtered to remove CLC and the supernatant was analyzed for lactic acid and gluconic acid by HPLC and for calcium by atomic absorption spectroscopy. The visual inspection demonstrated that CLC were formed in the solution with 0% gluconate after the first day of storage and CLC continued to accumulate over time. A minute amount of CLC was also visible in the solution with 0.5% gluconate after 21 d of storage, whereas CLC were not visible in the other solutions. The HPLC results indicated a higher concentration of calcium and lactic acid in the filtrate from the solutions containing added gluconate. Thus, sodium gluconate can increase the solubility of CaL₂.     

复合有机酸保鲜剂OAA-7的抑菌特性研究

本实验以复配保鲜剂OAA-7(主要成分为抗坏血酸、柠檬酸、乳酸、丙氨酸、氯化钠、氯化钙和丙三醇)为对象,研究OAA-7抑菌谱,以及温度、pH、保存条件对其抑菌活性的影响.结果表明,OAA-7抑菌活性强、pH作用范围广,性质稳定,保质期长,在高温下也有较高的活性;对革兰氏阳性细菌、革兰氏阴性细菌以及霉菌都有抑制作用.     

EFFICACIES OF ACETIC, LACTIC AND TWO MIXED ACIDS IN REDUCING NUMBER OF BACTERIA ON SURFACE OF LEARN MEAT

This study on sanitizing beef surfaces was designed to evaluate effects of mixtures of acetic, lactic, citric and ascorbic acids with individual solutions of acetic and lactic acids. Acetic acid (3%), lactic acid (3%), MA1 (2% acetic, 1% lactic, 0.25% citric and 0.1% L-ascorbic acids) and MA2 (2% lactic, 1% acetic, 0.25% citric and 0.1% L-ascorbic acids) solutions were applied to beef core samples of muscle inoculated with bacteria. Experimental variables were type, concentration and temperature of acid solutions and type of microorganisms. Overall, an increase in either acid concentration or treatment temperature decreased numbers of residual viable bacteria. Lactic acid solution was the most effective against S. typhimurium with a reduction of 2 log₁₀ at 70°C. For enterobacteria, acetic, lactic and MA2 solutions at 70°C resulted in a 1.5 log₁₀ reduction. MA2 was the most effective acid solution at both 45 and 70°C, whereas, lactic acid and the MA2 mixture did not differ in effectiveness at 20°C.     

Dietary tea catechins and iron-induced lipid oxidation in chicken meat, liver and heart

The aim of the research was to determine water binding and holding capacity and to measure the force and work of penetration of minced pork and beef cured with brine of varying concentrations of sodium chloride and lactic acid and then heated. M. biceps femoris was cut out from chilled pork and beef carcasses three times from each species. Minced meat was subjected to curing. Each of the 20 experimental treatments resulted from appropriate combinations of salt (0.0-2.0%) and lactic acid (0.0-1.5%). The individual concentrations of these two compounds differed by 0.5%. The addition of the curing brine containing only sodium chloride or only lactic acid caused an increase of water holding and binding capacity. The additions of curing brines containing various concentrations of mixtures of salt and acid cause lowering of water holding and binding capacity. Higher penetration force and work had to be applied for pork than for beef samples. With the increase of salt and lactic acid concentrations applied together, after the initial increase of the penetration force and work, their values were found to decrease at higher concentrations of mixtures of these substances in meat.     

Acetic, Lactic, and Hydrochloric Acid Effects on Staphylococcus aureus 196E Growth Based on a Predictive Model

Mathematical models were developed with a modified Gompertz function to predict Staphylococcus aureus 196E growth, where pH was altered with either acetic, lactic or hydrochloric acid. S. aureus 196E was inoculated into broth formulated with 0.5, 4.5 or 8.5% sodium chloride, adjusted to pH 5.0, 6.0 or 7.0, and incubated aerobically at 12, 20 or 28°C. Each model adequately predicted log growth, and some interactive relationships between independent variables upon population growth were significant (p<0.05). Predictions of growth showed that acetic was generally more inhibitory than lactic or hydrochloric acids.     

Amino Acid Composition of Protein Fractions Extracted from Phaseolus Beans and the Field Bean (Vicia faba L.)

Protein fractions were extracted sequentially with 2% sodium chloride, 30% isopropyl alcohol, 4% lactic acid and 0.5% potassium hydroxide from three varieties of adzuki beans, kafae and red kafae bean, three varieties of lima beans and red lima bean, two varieties of kidney beans and field bean that were grown in the tropics and sub-tropics. The sodium chloride extract had the highest range of protein concentration (51.2 to 81.4%). The sodium chloride extract was separated into two fractions based on solubility in water. The amino acid compositions of the flour from the seed and of the two fractions from the sodium chloride extract were determined. High contents of lysine, aspartic acid, glutamic acid and leucine were obtained, whereas the sulphur-containing amino acids contents were low.     

元分析方法评估食品加工对果菜中农药残留的作用

本文采用元分析方法评估食品加工对果类蔬菜中农药残留作用。通过多个数据库文献搜索、数据采集、元分析统计计算,获得特定食品加工方式对果菜中农药残留作用的响应比值、实验间变异及置信区间,并对实验数据进行了同质性Q检验。结果显示研究所取数据具有同质性,自来水清洗、多种溶液清洗、去皮、水煮、清炒、漂烫、烘烤对果菜中农药作用的响应比值均小于0.6,说明食品加工对去除果菜中农药残留有较好作用,可达到40%以上;其中漂烫和烘烤的响应比值分别为0.04和0.01,农药去除效果极佳,可达到95%以上;与自来水清洗相比,乙酸溶液、氯化钠溶液、碳酸钠溶液、碳酸氢钠溶液清洗对农药去除均有较好的效果。元分析获得食品加工对果菜中农药残留作用的响应比值可作为加工因子用于食品安全风险评估中,并可指导果菜安全消费。