Canned Dry Bean Quality as Influenced by High Temperature Short Time (HIST) Steam Blanching

High temperature short time (HTST) steam blanched dry beans had greater drained weights and shear values than water blanched dry beans. Moisture content of dry beans was greater after water blanching. Subjective grade was closely related to drained weights and shear values, and HTST steam blanched dry beans had better subjective grades than water blanched dry beans. Water blanched dry beans were lighter in color than HTST steam blanched dry beans. As length of HTST steam blanch was increased, Agtron color of the beans darkened. High quality canned dry beans can be produced with HTST steam blanching with energy and time savings, but differences between water and HTST steam blanching and canning quality is highly dependent on cultivar and length of HTST steam blanch.     

Lipoxygenase as Blanching Index for Frozen Vegetable Soybeans

Blanched samples of frozen vegetable soybeans using peroxidase (POD) and lipoxygenase (LIP) as blanching indices were compared with unblanched samples during storage by sensory evaluation, vitamin C determination and remaining enzyme activity. Samples using LIP and POD as blanching indices showed no significant differences in sensory quality during 160-day frozen storage, while both treatments were significantly different from unblanched samples. Vitamin C in samples using LIP as blanching index was higher than that in unblanched ones but not significantly different from that in samples using POD as an index. Samples using LIP as blanching index had 11.5% POD activity but no LIP activity, while blanched samples using POD as blanching index had no LIP or POD activities during storage.     

Systematic Application of Time Temperature Integrators as Tools for Control of Frozen Vegetable Quality

ABSTRACT: The application of Time Temperature Integrators (TTI) for quality monitoring and control of frozen vegetable products was studied. Kinetic modeling of characteristic shelf life indices of frozen green peas and white mushrooms was conducted from - 3 to - 20 °C. Effect of temperature on color and vitamin C changes was modeled by the Arrhenius and WLF equations and validated at dynamic temperature conditions. Temperature dependence expressed by the value of activation energy ranged from 79 to 155 kJ/mol. Response kinetics of 2 enzymatic TTI were also obtained and validated. Activation energies of response were 61 and 100 kJ/mol. Based on kinetics, suitable TTI predicted the product remaining shelf life at different temperature exposures from production to consumption.     

Energy Utilization During Blanching (Water vs Steam) of Sweet Corn and Subsequent Frozen Quality

A counter-flow water blancher required 44% less steam to blanch corn than a conventional steam tunnel blancher. On an hourly steam consumption basis, the counter-flow water blancher was 31% more efficient than the steam blancher. Total product yield was 1.5% greater with the steam blancher than with the counter-flow water blancher. Drip loss of the corn was greater with the counter-flow water blancher than with the steam blancher, but moisture content of the corn was also greater. Yellow color was darker for the counter-flow water blanched corn than the steam blanched. The use of the counter-flow water blancher to blanch corn resulted in substantial energy savings with little or no difference in quality when compared to the steam blanched product.     

Changes in Quality of All-Beef and Soy-Extended Patties as Influenced by Freezing Rate, Frozen Storage Temperature, and Storage Time

All-beef and soy-extended patties were frozen to - 18°C in either 24, 48, 72 or 96 hr and stored at -23, -18 or -7°C for 0, 6, 9, 12, 18 or 24 months prior to evaluating various quality factors. In evaluations made immediately post-freezing, freezing to - 18°C in 96 hr reduced beef flavor intensity and juiciness for both types of patties. Except for juiciness, storage at -7°C for just 6 months produced sizeable reductions in quality. Longer storage produced gradual, but continual deteriorations in quality, especially color, odor, flavor and TBA values. Inclusion of soy reduced many of the negative effects of storage on quality.     

高温蒸汽瞬时漂烫对黑牛肝菌酶活和品质影响的研究

研究了高温瞬时蒸汽对黑牛肝菌的过氧化物酶(POD)和多酚氧化酶(PPO)活性的影响,并研究了对黑牛肝菌几种重要营养成分的影响,包括总酚、可溶性总糖、VC以及可溶性蛋白。通过时间(s)、物料量(g)、蒸汽压力(MPa)的单因素试验,设计正交试验,对POD、PPO、总酚、总糖、VC、可溶性蛋白进行综合评价分析,得出最佳的试验条件:高温蒸汽瞬时漂烫时间为30 s、物料量300 g、蒸汽压力0.3 MPa,综合评分值最高。高温蒸汽漂烫最优结果与最佳的热水漂烫处理进行比较,体现了高温蒸汽漂烫的优势。     

Protein Stability of Frozen Milk as Influenced by Storage Temperature and Ultrafiltration

Milk and milk concentrates containing 12–35% total solids were stored at 0, –2, –4, –6, –8, –12, and –20°C and protein stability of the thawed products was evaluated periodically. Samples stored at –4 to – 12°C exhibited poorer protein stability than samples stored at higher or lower temperatures. Ultrafiltered (UF) skimmilk with permeate: retentate ratios of 10:90, 20:80, and 30:70 were stored at –8°C and they remained stable at least three times longer than frozen control samples of UF skimmilk stored at the same temperature. When the extent of UF was increased to 40:60, protein stability in the frozen retentate declined somewhat as compared to that of less concentrated retentates.     

Quality Attributes of High Temperature Short Time Air Puffed Ready-to-eat Potato Snacks

The effects of process parameters for high temperature short time (HTST) air puffing viz. puffing temperature (175–275°C), puffing time (15–75s), moisture content (30–40%), and air velocity (2.4–4.8m/s) on quality attributes such as expansion ratio (ER), bulk density (BD), colour (L-value), and texture (hardness) of ready-to-eat (RTE) potato snacks were investigated, based on central composite design. Increasing puffing temperature resulted in potato snack with a higher ER, lower hardness, lower BD, and lower L-value. Increasing puffing time produced lower hardness and lower L-value but no significant effect on the ER and BD. Higher moisture content increased ER and L-value but reduced hardness and no significant effect on the BD. Increasing air velocity resulted in potato snack with a higher ER, higher L-value, lower BD and lower hardness.     

超高压和高温短时杀菌对绿色复合果蔬汁的杀菌效果与品质影响

通过感官评价,综合基本理化指标得出了一种较优的绿色复合果蔬汁的配方,并对比超高压(high hydrostatic pressure,HHP)和高温短时杀菌(high temperature short time,HTST)处理前后及其在4 ℃贮藏过程中的杀菌效果和理化品质变化。结果表明:对复合果蔬汁分别进行HHP(600 MPa/5 min)处理和HTST杀菌(86 ℃/15 s)处理后,果蔬汁中菌落总数从5.18 lg CFU/mL,下降至1.07 lg CFU/mL和1.11 lg CFU/mL,霉菌酵母、乳杆菌和嗜冷菌均未检出,达到国家要求的果蔬汁卫生标准;HHP处理后的果蔬汁总酚含量为43.645 μg/mL,显著高于HTST绿色复合果蔬汁;与HTST处理相比,HHP处理可以更好地保持复合果蔬汁的悬浮稳定性、色泽和抗氧化性等营养和品质指标。在4 ℃,15 d的贮藏期间,经HHP处理和HTST杀菌后的复合果蔬汁微生物指标均未超出国家卫生标准,且经HHP处理后的复合果蔬汁的悬浮稳定性、色泽品质、总酚含量和抗氧化能力等各项品质指标均优于HTST杀菌组。因此,HHP绿色复合果蔬汁保持了更好的品质。     

Alterations of Bovine Sarcoplasmic Proteins as Influenced by High Temperature Aging

SUMMARY— Effects of high temperature aging upon certain characteristics of bovine I. dorsi muscle were studied. Paired wholesale ribs of carcasses were obtained subsequent to slaughter. The left rib of each pair was held at 30°C for 24 hr, then stored at 3°C. Analogous right ribs were immediately stored at 3°C. A sampling schedule of 0, 1, 2, 3, 4, 7 and 10 days was followed.
There were minor variations in moisture, pH, tyrosine-tryptophan indices of non-protein nitrogenous compounds and expressible moisture ratios between treatments and with time. These differences were not statistically significant.
Up to three days storage, extractability of water soluble protein was greatest from muscles held at the elevated temperature. After the third day, however, extractability was greater for muscles held at 3°C.
Color differences between muscles treated via the two storage temperatures were marked. Absorbance ratios (422.280 mp) of extracts showed that muscles held at the high temperature had higher extractable levels of oxymyoglobin than ribs held at 3°C. This difference remained apparent throughout the aging period.
Results of DEAE-cellulose ion exchange chromatography of the sarcoplasmic proteins showed only minor variations in profiles between the two aging treatments. Alterations did appear with time. Profile alterations did not appear related to anticipated increases in tenderness.     

超高压和高温短时杀菌对樱桃汁品质的影响

比较了超高压(high pressure processing,HPP,550 MPa/2 min)和高温短时(high temperature short time,HTST,95 ℃/15 s)杀菌对樱桃汁中微生物、总酚、维生素C、花色苷、抗氧化能力以及感官品质的影响,并分析了4 ℃贮藏樱桃汁品质变化。结果表明:樱桃汁经过HPP和HTST杀菌后细菌总数小于100 CFU/mL、霉菌和酵母菌未检出,两者对樱桃汁均具有较好的杀菌效果;两种方式杀菌后樱桃汁中绿原酸和矢车菊素-3-芸香糖苷含量显著降低(p<0.05),HPP樱桃汁中绿原酸与矢车菊素-3-芸香糖苷保留率分别为95.4%±8.0%和77.7%±13.8%,显著高于HTST樱桃汁(p<0.05)。HPP对樱桃汁果胶、总酚、维生素C、天竺葵素-3,5二葡萄糖苷含量无影响,儿茶酚含量提高了4.6%;HTST降低了樱桃汁果胶、总酚、儿茶酚、维生素C、天竺葵素-3,5二葡萄糖苷的含量;两种果汁抗氧化能力无显著变化(p>0.05)。HPP樱桃汁在香气、滋味、颜色方面比HTST樱桃汁具有更好的感官品质。4 ℃冷藏期间,两种樱桃汁中细菌总数缓慢升高,但霉菌与酵母菌仍未检出;HPP樱桃汁中总酚、绿原酸、儿茶酚、维生素C、矢车菊素-3-芸香糖苷含量以及抗氧化能力均高于HTST樱桃汁。因此,HPP樱桃汁保持了更好的品质。     

Viscoelastic Behavior of Melon Tissue as Influenced by Blanching and Osmotic Dehydration

ABSTRACT: Viscoelastic properties of melon tissue exposed to steam blanching and osmotic dehydration (atmospheric or under vacuum) in glucose aqueous solutions were analyzed in a dynamic rheometer using oscillatory shear and creep tests. The storage modulus (G') greatly exceeded the viscous modulus (G') for raw and treated melon tissues, but the elastic component was partially lost because of processing. Blanching caused less than a 1 -fold decrease in G', whereas osmotic dehydration resulted in approximately a 3-fold decrease in G'relative to the untreated melon. Both moduli showed a weak dependence on frequency, with greater slope of the G'frequency lines for treated samples. A mechanical model, consisting of a spring in series with 2 Voigt elements and a dashpot element, properly predicted the creep compliance response for all melon samples. In general, overall compliance significantly increased by the treatments. The instantaneous elastic compliance and the viscoelastic compliances were the most sensitive viscoelastic parameters for distinguishing the differences in cell wall structure among osmotically dehydrated sample at atmospheric pressure and the tissues exposed to the other osmotic treatments. In contrast, G'modulus did not show an ability to evidence these structural differences because there were no significant differences in the G'values of osmotically dehydrated tissues at atmospheric pressure or in vacuum, with or without calcium addition.     

Bingrsquo; Sweet Cherry (Prunus avium L) Quality as Influenced by Wax Coatings and Storage Temperature

The use of wax coatings on cherry fruit reduced moisture loss during ambient storage, enhanced cuticular diffusive resistance and retarded v the incidence of decay. After ambient storage, cherry fruit treated s with wax coatings were firmer than the other treatments, but the use of wax did not reduce the incidence of surface pitting, stem discoloration or stem moisture loss. Fruit packed in a poly liner were similar in quality to fruit with wax coatings, but stems on fruit in poly liners had better color and moisture. Storage temperature control was the best method to maintain high quality fruit. Cherry fruit and stems c stored at 0°C were superior to fruit and stems stored at 4.5°C or 10°C in most quality attributes.     

Textural Properties and Sensory Quality of Processed Sweetpotatoes as Affected by Low Temperature Blanching

Sweetpotatoes (SP) stored for 9–12 mo after harvest were cut into cylindrical pieces and, following factorial experiments and response surface design, were blanched at 50–80°C for 15–274 min. Instrumental textural properties were measured by uniaxial compression and texture profile analysis. Samples of selected blanching treatments were canned in syrup for textural and sensory evaluations. Both blanching temperature and time had significant effects on firmness. Optimal temperature for maximal firmness retention was about 62°C. For canned SP, the 62°C blanched samples were more intact (2–3-fold) and firmer (2–7-fold) than controls. Sensory texture and overall acceptability were greatest for samples blanched at 62°C for 30 or 45 min before canning.     

漂烫时间及贮藏温度对香椿嫩芽品质的影响研究

以香椿嫩芽为研究对象,研究不同漂烫时间及贮藏温度对香椿嫩芽品质的影响,以期为香椿嫩芽的加工提供理论指导。以烫漂后香椿嫩芽感官及品质指标VC、多酚、黄酮、可溶性蛋白、亚硝酸盐及多酚氧化酶(PPO)各项变化对香椿嫩芽品质进行综合评价。结果表明:较短的漂烫时间可以保持香椿嫩芽外观及口感;对香椿嫩芽营养成分影响较小,烫漂可显著降低香椿嫩芽中的亚硝酸盐含量且可显著降低多酚氧化酶酶活性;在-2℃贮藏180 d,香椿嫩芽仍保持较好的品质。因此0.5 min为香椿嫩芽最佳烫漂时间,-2℃贮藏可以较好保持烫漂香椿嫩芽的品质。     

烫漂温度及空气炸时间对鲶鱼鱼皮品质的影响

为了解烫漂温度及空气炸时间对鲶鱼鱼皮品质的影响,本文研究了50、70、90 ℃烫漂后鲶鱼鱼皮的蒸煮损失率和热稳定性,在烫漂的基础上分别炸制2、4、6、8、10、12 min后对其水分、脂肪、脆度、横向弛豫时间（T₂）进行了测定,并对不同烫漂温度及其空气炸12 min的鱼皮微观结构进行了分析。结果表明:70 ℃烫漂的鱼皮蒸煮损失率为2.15%,热稳定性温度分别为121.97、146.88 ℃,在空气炸12 min时水分含量为2.89%,脂肪含量为10.85%,形变距离为0.13 mm;相比较50 ℃和90 ℃,70 ℃烫漂的鱼皮,蒸煮损失率适中,热稳定性较好,在空气炸12 min时,水分含量最低,形变距离最小,脂肪含量较低,结构均匀平整。由此可见,70 ℃烫漂下的空气炸鱼皮整体更利于后期产品的开发。     

不同漂烫温度对苦菜品质指标的影响

本文主要研究了苦菜在不同漂烫温度下的品质指标变化。实验表明，苦菜漂烫时，随漂烫温度的升高，叶绿素、糖、POD和维生素C的含量都有较大幅度的降低，而蛋白质和钙的含量则基本保持恒定。     

超高压和高温瞬时杀菌对蓝莓汁品质影响的比较

主要研究了2种杀菌方式对蓝莓汁品质的影响。一种是550 MPa、5 min的超高压杀菌,另一种是121℃、5 s的高温瞬时杀菌。通过测定杀菌后蓝莓汁的菌落总数、悬浮稳定性、色差值、花色苷含量和理化性质等指标,证实超高压杀菌在杀菌的同时较好地保持了蓝莓汁原有的品质、色泽及营养。     

Optimization of Low Temperature Blanching of Frozen Jalapeño Pepper (Capsicum annuum) using Response Surface Methodology

The effects of low-temperature long-time blanching of diced jalapeño pepper prior to freezing on extrusion force, color and pH of the product were evaluated and optimized by response surface methodology. The blanch temperature was the most important factor, while hold time had no significant effect on product quality. Maximum extrusion force and color parameter a*(green-red) correlated with temperature. The pH and the color parameters L*(brightness) and b*(blue-yellow) showed no significant variation with the experimental variables. The recommended blanch temperature of 55°C produced a firmness value of 779N and a color value of –10.55 of parameter a* in frozen jalapeño peppers.