正交试验优化干装苹果罐头固化护色剂配方

为了优化干装苹果罐头加工工艺和稳定产品质量,以碱性钙(氧化钙、氢氧化钙)、无机钙(氯化钙、碳酸钙、硫酸钙)、有机钙(乳酸钙、醋酸钙、丙酸钙)为固化剂,研究不同固化剂对苹果干装罐头质地参数(硬度、回复性、弹性指数、咀嚼性、内聚性)、感官品质、果胶及果胶酸钙的影响,并采用正交试验法,研究柠檬酸质量浓度、Ca2+质量浓度和D-异抗坏血酸钠质量浓度对干装苹果罐头感官品质和色泽的影响,优化固化护色剂最佳配方。结果表明:与其他处理相比,经碱性钙(氧化钙和氢氧化钙)处理的干装苹果罐头硬度适中,回复性、弹性指数、咀嚼性、内聚性、感官品质较好,果胶含量显著降低,果胶酸钙含量显著升高。固化护色剂的最佳配方为25g/L柠檬酸+2.8g/L氧化钙+3g/LD-异抗坏血酸钠。碱性钙对干装苹果罐头有较好的固化作用,此配方有利于提高干装苹果罐头产品质量标准。     

干装苹果罐头贮藏过程中质地与细胞壁组分的变化

以干装苹果罐头为研究对象,采用TPA质构分析和乙醇不溶物（AIR）法,研究干装苹果罐头（4±1） ℃和常温贮藏过程中质地和细胞壁组分的变化,并探讨其质地参数和细胞壁组分变化的相关性。结果表明,低温贮藏能延缓干装苹果罐头质地和细胞壁组分的变化,（4±1） ℃贮藏的在24个月时硬度、回复性、咀嚼性、内聚性的变化率分别为0.74%、1.92%、0.25%、0,水溶性果胶（WSF）降低率为5.45%、螯合剂溶性果胶（CSF）和碳酸钠溶性果胶（NSF）升高8.88%和24.49%、半纤维素组分（HF）降低14.15%;常温贮藏的在12个月时硬度、回复性、咀嚼性、内聚性的降低率分别为3.93%、3.85%、11.36%、3.45%,WSF降低率为7.27%、CSF和NSF升高0.58%和4.08%、HF降低14.41%,质地参数与WSF呈负相关,与CSF、NSF、HF呈显著正相关。     

干装苹果罐头贮藏过程中质地与细胞壁组分的变化

以干装苹果罐头为研究对象,采用TPA质构分析和乙醇不溶物(AIR)法,研究干装苹果罐头(4±1)℃和常温贮藏过程中质地和细胞壁组分的变化,并探讨其质地参数和细胞壁组分变化的相关性。结果表明,低温贮藏能延缓干装苹果罐头质地和细胞壁组分的变化,(4±1)℃贮藏的在24个月时硬度、回复性、咀嚼性、内聚性的变化率分别为0.74%、1.92%、0.25%、0,水溶性果胶(WSF)降低率为5.45%、螯合剂溶性果胶(CSF)和碳酸钠溶性果胶(NSF)升高8.88%和24.49%、半纤维素组分(HF)降低14.15%;常温贮藏的在12个月时硬度、回复性、咀嚼性、内聚性的降低率分别为3.93%、3.85%、11.36%、3.45%,WSF降低率为7.27%、CSF和NSF升高0.58%和4.08%、HF降低14.41%,质地参数与WSF呈负相关,与CSF、NSF、HF呈显著正相关。     

钙处理对干装苹果罐头质地的影响

采用质地多面分析方法(TPA),以清水处理为对照,研究碱性钙(氧化钙、氢氧化钙)、无机钙(氯化钙、碳酸钙、硫酸钙)、有机钙(乳酸钙、醋酸钙、丙酸钙)对干装苹果罐头质地参数(硬度、回复性、弹性指数、咀嚼性、内聚性)的影响,并对TPA参数之间及其与感官品质间的相关性进行了研究.结果表明:与对照相比,除硫酸钙以外,各处理对干装苹果罐头质地均有明显的影响,经碱性钙(氧化钙和氢氧化钙)处理的干装苹果罐头硬度适中,回复性、弹性指数、咀嚼性、内聚性、感官品质均较好.回复性、弹性指数、咀嚼性、内聚性之间的相关性均显著,硬度与感官品质之间呈显著正相关关系.表明碱性钙对干装苹果罐头有较好的作用,并保持良好的质构.     

干装苹果罐头加工工艺

为了优化干装苹果罐头加工工艺和稳定产品质量,采用正交实验法,研究柠檬酸质量浓度、Ca2+质量浓度和D-异抗坏血酸钠质量浓度对干装苹果罐头感官品质和色泽的影响,优化固化护色剂的配方;并对新工艺和传统工艺加工的干装苹果罐头的杀菌效果进行了比较。结果表明:固化护色剂的优化配方为25 g/L柠檬酸+2.8 g/L CaCl2+3 g/L D-异抗坏血酸钠。采用新工艺使干装苹果罐头的杀菌公式优化为"5'-25'-30'杀菌温度98℃",杀菌时间缩短16.7%,新工艺生产的干装苹果罐头质量明显优于传统工艺生产的干装苹果罐头。     

苹果梨果实生育期果胶物质的研究

以开发利用苹果梨资源及果实质地的研究为目的,测定了苹果梨生育期果实中细胞壁物质(AIS)以及不同溶解性果胶的舍量.结果表明,随着果实成熟,AIS呈先上升后降低的趋势.果皮和果肉AIS中及鲜果果皮中果胶总含量均在果实膨大期含量较高,成熟后期呈下降的趋势,而鲜果果肉中果胶总含量在盛花后第50d含量较高,随后其含量下降,且其含量均低于果皮中的含量.幼果中以碱溶性果胶含量最多,为果胶的主要成分,成熟果中则以酸溶性果胶含量较多,碱溶性果胶含量次之;水溶性果胶和盐溶性果胶在整个生育期中所占比例较少.     

不同工艺条件对桔皮果胶钙产量的影响

为提高桔皮果胶钙的产量,以桔皮为原料,用钙盐析法沉淀果胶,利用单因素和正交分析法,探讨pH、盐析时间、盐析温度、氯化钙添加量等因素对果胶钙产量的影响.结果表明,pH、盐析时间和温度对果胶钙产量影响显著,氯化钙添加量对果胶钙产量的影响不显著.生产果胶钙的最适宜条件为:pH10.00,温度40℃,时间6h,CaCl2用量为7.2gCaCl2/100g干桔皮,此条件下的桔皮果胶钙产量为19.67％.本研究为生产果胶钙提供了一定的参考.     

不同酯化度果胶钙的结构特征与体外消化稳定性

为探究不同酯化度（DE）果胶形成的果胶钙的结构特征与消化稳定性,采用5种DE值的果胶与氯化钙反应获得5种DE的果胶钙,比较其产率、钙含量,红外、X衍射（XRD）、电镜（SEM）等结构特征与体外模拟消化稳定性。结果表明：果胶钙产率为50%～87%;DE=10%的果胶与Ca2+反应形成的果胶钙（DE10-CaP）的钙含量最高（88 mg/g）,DE59-CaP钙含量最低（43.6 mg/g）;果胶钙中Ca2+与羧酸根的结合形式为单齿配位结合型,并可分为3种结合区域,进一步完善了果胶钙的结合模式;XRD表明低酯果胶钙比高酯果胶钙多一处2θ=21.5°的衍射峰;SEM表明低酯果胶钙的表观结构更紧密,呈块状,高酯果胶钙则呈薄片状。体外模拟胃肠消化试验表明,高酯果胶钙的钙释放率及释放量更高。本研究有助于了解果胶钙的微观结构及应用性能。     

机械损伤对富士苹果采后软化生理的影响

以富士苹果为试材,研究了机械损伤后在5℃和18℃贮藏条件下对果肉颜色、果肉硬度、可溶性果胶和原果胶含量、纤维素含量及纤维素酶活性的影响.结果表明,机械损伤导致果肉L*、果肉硬度、原果胶含量、纤维素酶活性均快速下降;a*值显著上升;b*值、纤维素含量、可溶性果胶含量呈前期上升后期下降的趋势:在贮藏过程中,伤害部位的生理生化指标均显示了上升和下降的反复趋势.说明机械损伤破坏了细胞壁的组织结构,促进了果实的快速软化;随着贮藏期的延长,愈伤组织逐渐形成,从而达到伤害部位的自我修复.而且受伤果实在低温下贮藏各种生理代谢缓慢,有效地延缓了受伤果的快速衰老.     

基于果胶特性改变的罐藏黄桃质构软化机制

为探究罐藏黄桃质构品质变化及形成机理,本实验以‘金童5号’黄桃为原料制备罐头,提取罐藏黄桃果胶组分,即水溶性果胶(water soluble pectin,WSP)、螯合性果胶(chelator-soluble pectin,CSP)和碱溶性果胶(carbonate-soluble pectin,NSP),深入分析加工过程中罐藏黄桃不同组分的果胶含量、甲酯化度(degree of methoxylation,DM)、乙酰化度(degreeofacetylation,DAc)、分子质量及结构官能团等特性变化规律,解析加工过程中多聚半乳糖醛酸酶(polygalacturonase,PG)和果胶甲基酯酶(pectin methyl-esterase,PME)的活力变化。结果表明:预煮及热杀菌处理能显著改变罐藏黄桃果肉的质构品质;相比较新鲜黄桃样品,经预煮和杀菌的罐藏黄桃果肉WSP和CSP含量上升,NSP含量无显著差异(P0.05);WSP和CSP的DM均呈下降趋势,WSP的DAc显著降低(P0.05),CSP分子质量先增加后减小。此外,傅里叶变换红外光谱结果与DM测定结果一致。追踪加工过程中果胶酶活性发现,PME经预煮及热杀菌后已被完全钝化,PG活力整体仍保持较高活性。经相关性分析可知,酶及各果胶组分与质构品质之间均呈现不同程度的相关性,明确加工过程中酶及果胶结构特性变化是影响罐藏黄桃质构形成机制的主要因素。本实验为后续生产高品质罐装黄桃、延长货架期等提供理论基础。     

Calcium and Oxalate Ions Effect on the Texture of Canned Apricots

SUMMARY– Softening of canned apricots was accompanied by increase in soluble pectin and syrup viscosity. Calcium ions have the ability to decrease, to some extent, the movement of pectic material from the fruit to the syrup. This might be explained by the ability of calcium ions to make a bridge between polygalacturonic acid units, thus producing larger molecules which bind the cells together at the middle lamella. Added oxalate ions removed calcium from pectin in the cell wall, causing an increase in water-soluble pectin in the syrup and softening of texture. The mineral contents of canned apricots from three growing areas were determined by flame spectrophotometry. Low potassium in the fruit seems to be related to low pH in the cell sap, causing hydrolysis of pectic materials through hydrolysis ion catalysis and softening during heat processing and storage.     

Firmness and Cell Wall Characteristics of Pasteurized Jalapeño Pepper Rings as Affected by Preheating and Storage

Changes in cell wall pectic substances, degree of pectin methylation, bound calcium and firmness were determined in preheated and nonpreheated fresh pack jalapeño pepper rings stored for 5 mo. Pepper rings preheated for 60 min at 50°C in a brine solution (8% NaCl and 0.2% CaCl₂, were firmer, had more nonextrctable pectins (NXP), more bound calcium, less water-soluble and chelator-soluble pectins (CSP), and less pectin methylation than nonpreheated pepper rings. The greater formation and maintenance of nonextractable pectins, which resisted acid hydrolysis during pasteurization and storage is probably an important factor in firming.     

Effects of Gamma Irradiation on the Texture of Minimally Processed Apple Slices

ABSTRACT: Fresh-cut apples with or without calcium treatments were irradiated at doses up to 5 kGy at 0.4 and 2 kGy.h^-1 dose rates with a Co⁶⁰ source in 0, 21, and 100% O₂ atmospheres. Firmness decreased as irradiation dose increased beyond a 0.34 kGy threshold. High dose rate initially resulted in less softening compared to low dose rate, but dose rate became insignificant upon storage. Irradiation atmosphere did not affect firmness. Softening of irradiated slices correlated positively with water-soluble pectin, and negatively with oxalate-soluble pectin content. Calcium prevented irradiation-induced softening of thin slices (3-4 mm thick), but was not effective with thicker wedges due to limited penetration.     

RELATIONSHIP OF TREATMENT OF FRESH STRAWBERRIES TO THE QUALITY OF FROZEN FRUIT AND PRESERVES1

‘Cardinal’ strawberries were hand picked and stored 1 day at 21°C to enhance softening. Three separate preprocessing experiments were conducted to determine the effects of style of pack, 0.18% calcium (Ca) dips, 0.3% low methoxyl pectin (LMP), 40° Brix sucrose dips, heat of 70°C, vacuum at 172 mm Hg and drying to 70% moisture on quality and firmness of frozen-then-thawed and preserved strawberries. The greatest firming effect on frozen-then-thawed fruit was due to Ca and pectin. Sliced fruit was firmed more than whole fruit by the Ca and pectin treatments. Drained weight loss was reduced by pectin, Ca, sucrose, heat and vacuum in frozen-then-thawed fruit. Drained weight losses were the same or greater among treatments in preserves. The firmness and wholeness of preserves was increased by Ca, vacuum, 40° Brix sucrose, heat and to a lesser extent drying, but individual effects were not additive. The drying treatment reduced color quality.     

1-MCP处理对“岳帅”苹果冷藏软化及相关生理指标的影响

研究1-甲基环丙烯(1-methylcyclopropene,1-MCP)处理对"岳帅"苹果低温贮藏期间与软化相关的主要物质含量及酶活性的影响,探讨1-MCP处理对"岳帅"苹果果实软化的调控机理,为"岳帅"苹果贮藏保鲜提供理论依据。以"岳帅"苹果为研究对象,使用0.0、0.5、1.0、2.0μL/L的1-MCP处理后,于(0.0±0.5)℃、相对湿度90%~95%的冷库内贮藏,定期测定果实硬度、呼吸强度、乙烯释放量、细胞壁组成成分及相关酶活性。"岳帅"苹果采后呼吸强度和乙烯释放量均于第30天时达到峰值,多聚半乳糖醛酸酶(polygalacturonase,PG)也在第30天达活力高峰,果胶甲酯酶、纤维素酶(cellulose,Cx)、β-葡萄糖苷酶第45天达活力高峰,同时果实可溶性果胶含量迅速上升,原果胶、纤维素含量不断下降。0.5μL/L 1-MCP处理可推迟果实呼吸强度高峰、乙烯释放量高峰、PG和Cx活力高峰的出现,对抑制可溶性果胶含量升高和原果胶含量的降低作用显著(P0.05),但对冷藏结束时果实硬度的降低抑制效果不显著(P0.05);1.0μL/L和2.0μL/L 1-MCP处理对果实呼吸强度、乙烯释放量、细胞壁降解酶、可溶性果胶含量均有显著抑制作用(P0.05),并且能显著抑制果实硬度下降(P0.05)。"岳帅"苹果在冷藏期间原果胶、纤维素不断被分解,可溶性果胶不断生成,果实硬度迅速下降;除PG外,各细胞壁降解酶活力高峰均出现在呼吸强度和乙烯释放量高峰之后。1-MCP处理通过改变"岳帅"苹果呼吸强度和乙烯释放量,抑制果实细胞壁降解酶活性并推迟活性高峰,从而减缓果实细胞壁组成成分降解,抑制果实软化。1.0μL/L和2.0μL/L的1-MCP处理效果较为显著。     

Effect of partial substitution of NaCl with KCl on proteolysis of halloumi cheese

The effect of substitution of NaCl with Potassium chloride (KCl) in brine solution on proteolysis of halloumi cheese was investigated. Halloumi cheeses were made and kept in 4 different brine solutions (18% w/w), including only NaCl (HA; control); 3NaCl:1KCl (w/w) (HB); 1NaCl:1KCl (w/w) (HC); 1NaCl:3KCl (w/w) (HD); and stored for 56 d at 4 °C. Proteolysis was assessed using water-soluble nitrogen (WSN), trichloroacetic acid-soluble nitrogen (TCA-SN), phosphotungstic-soluble nitrogen (PTA-SN), urea polyacrylamide gel electrophoresis (urea-PAGE), and peptide patterns. WSN and TCA-SN contents were similar in all experimental cheeses. Peptide patterns of the pH 4.6 N fraction and urea-PAGE showed no significant difference between halloumi cheeses kept in various NaCl/KCl mixtures (HB, HC, HD) and control (HA). Sodium and potassium contents showed positive correlations with WSN and PTA-SN. There was an inverse correlation between calcium (Ca) contents and WSN and PTA-SN. Correlations between Ca and Na or K were negative at the same salt treatment.     

麻竹笋罐头贮藏过程中质构、果胶和色泽的变化

以麻竹笋为实验原料,研究麻竹笋罐头在常温（25 ℃）和低温（4 ℃）贮藏过程中质构、果胶和色泽的变化,并探讨麻竹笋罐头的硬度与果胶变化的相关性。结果表明：麻竹笋罐头在贮藏过程中硬度、原果胶和水溶性果胶含量逐渐下降,贮藏120 d后,常温贮藏和低温贮藏条件下麻竹笋的硬度分别下降39.5%和27.1%,原果胶含量分别下降66.4%和62.8%,水溶性果胶含量分别下降68.1%和75.7%。各果胶组分与硬度之间呈现较好的相关性,而原果胶与硬度之间的相关性高于水溶性果胶与硬度之间的相关性。麻竹笋罐头贮藏过程中亮度值L*和红绿值a*逐渐减小,黄蓝值b*逐渐增加;常温和低温分别贮藏30 d和70 d时,总色差ΔE＞2。     

Firmness and Cell Wall Characteristics of Pasteurized Jalapeño Pepper Rings Affected by Calcium Chloride and Acetic Acid

Pepper rings packed in brine containing CaCl₂ were firmer, had higher bound calcium, chelator soluble pectin and pectin DE, and less water-soluble pectin (WSP) than peppers packed in brine containing no CaCl₂. Pepper rings packed in low acid brines (1% and 1.2% acetic acid) were firmer and had less WSP than those packed in high acid brine. Those samples (4% acetic acid) resulted in softening and pectin solubilization, but CaCl₂ resulted in less softening. Monosaccharide composition of cell walls was not affected by CaCl₂ or acetic acid. Firmness retention in CaCl₂ treated samples was probably due to greater association between calcium ions and pectic substances, which resisted acid hydrolysis.     

Effect of Fertilization, Postharvest Handling and Blanching Temperature on the Drained Weight of Canned Summer Squash

There was no apparent effect on drained weight or firmness when three rates of calcium fertilization and two rates of potassium fertilization were applied to a test planting from which two harvests of raw summer squash were canned. However, high Ca (L₂) decreased dry matter and increased structural carbohydrates and tissue Ca in the canned product. Precooling increased drained weight and dry matter, but drastically reduced firmness of the canned product. Noncooled canned squash had lower drained weights and pH, but greater firmness and higher water soluble pectin and cellulose content. Blanching at 99°C increased drained weight; blanching at 88°C decreased drained weight, but increased calgonsoluble pectin content.