蓝鳍金枪鱼不同部位肌肉的营养与主要风味分析

为科学评价蓝鳍金枪鱼(Thunnus thynnus)不同部位肌肉营养与风味特征,对比分析了其背部和腹部肌肉的基本营养成分、氨基酸组成、脂肪酸组成和挥发性风味物质。结果显示,除灰分外,蓝鳍金枪鱼背部和腹部肌肉的水分、粗蛋白和粗脂肪含量差异显著;背部、腹部粗蛋白含量分别为24.70 g/100 g和18.61 g/100 g;背部、腹部粗脂肪含量分别为19.34 g/100 g和30.29 g/100 g。蓝鳍金枪鱼背部和腹部肌肉氨基酸总量分别达到(22.07±0.74) g/100 g和(16.57±0.47) g/100 g,差异显著(P<0.05)。必需氨基酸与氨基酸总量的比值均在40%左右,必需氨基酸与非必需氨基酸含量的比值均大于60%,接近于FAO/WHO推荐的蛋白质营养评价的理想模式,属于优质蛋白。谷氨酸的含量均最高,其次为天冬氨酸,胱氨酸含量最低。背部和腹部肌肉鲜味氨基酸占氨基酸总量的比例分别为34.93%和35.91%。背部和腹部肌肉中分别检测出24种和29种脂肪酸,各脂肪酸含量差异显著(P<0.05);饱和脂肪酸中肉豆蔻酸(C14:0)、棕榈酸(C16:0)...     

Development of flavor-related metabolites in cherimoya (Annona cherimola Mill.) fruit and their relationship with ripening physiology

Flavor is one of the most important attributes of fresh fruit for the consumer, and is affected by several factors, including genotype, maturity stage, and environmental conditions. Flavor-related metabolites were characterized in two important cherimoya varieties, cv. Concha Lisa and cv. Bronceada, during fruit ripening. The most important sugars present were glucose, fructose and sucrose, and only fructose and glucose increased during ripening. The most important acids were tartaric, malic and citric acids, and all increased as ripening progressed. Overall aroma profile was mainly determined by esters and terpenes in both varieties. Ester compounds such as ethyl hexanoate, butyl butyrate and hexyl propanoate increased during ripening. The activity of alcohol acyl transferase also increased during fruit ripening concomitant with ester accumulation. Terpenes, such as α and β-pinene, showed a reduction during ripening, whereas others, such as myrcene and limonene, increased.     

5份糯玉米改良系呈味氨基酸的配合力分析

以9份糯玉米自交系为材料，采用NCⅡ遗传交配设计，配制4×5不完全双列杂交组合，基于鲜子粒冻干、磨粉方式，采用近红外检测技术测定6种呈味游离氨基酸含量。结果表明，糯玉米组合呈味氨基酸变幅为0.13～8.05 g/mg，脯氨酸含量最高；WX156、WX159等改良系具有较高的呈味氨基酸一般配合力(GCA)。筛选得到B17×WX159、B13×WX156等高呈味氨基酸含量组合。相关分析表明，可溶性糖、皮渣率及谷氨酸含量与糯玉米口感紧密相关。     

干法制粒压片制备马波沙星风味片的研究

为制备马波沙星风味片，通过颗粒一次成型率，适口性、脆碎度、溶出度、批间重复性进行质量评价，以单因素实验筛选处方，正交试验优化处方，得到马波沙星风味片最佳处方为：马波沙星10%、乳糖24%、微晶纤维素37.5%、预胶化淀粉12%、鸡肝粉7.5%、羟丙基纤维素5%、低取代羟丙基纤维素3%、硬脂酸镁1%,采用干法制粒压片工艺，避免了溶剂的使用，操作简单，产品质量稳定，处方成本低，更易推广使用，在临床应用中具有广阔前景。     

The effect of delaying harvest date on fruit quality and storage of late highbush blueberry cultivars (Vaccinium corymbosum L.)

The effect of delaying harvest on fruit quality and storage life was measured for the late-season highbush blueberry cultivars ‘Aurora’, ‘Elliott’ and ‘Liberty’. In all three cultivars as fruit ripened, there was a steady decline in TA while SS remained stable, indicating that the fruit were becoming sweeter. This was supported by taste panel perceptions of greater sweetness associated with later harvested fruit. There was also a significant overall reduction in fruit firmness and storage life as the percentage of blue fruit at harvest increased; however, a significant interaction for storage life between crop ripeness and cultivar was observed, indicating that the fruit of some cultivars were less influenced by overall crop ripeness than others. The storage life of ‘Elliott’ was significantly affected negatively by crop ripeness, while ‘Aurora’ and ‘Liberty’ were not. ‘Liberty’ produced the highest percentage of sound fruit of the three cultivars and its fruit stored the longest, suggesting that ‘Liberty’ and ‘Aurora’ fruit can be left longer on the bush before harvesting than ‘Elliott’ without significantly damaging storage life. This would allow ‘Aurora’ to develop a sweeter flavor before shipping. The physicochemical and sensory evaluations were highly correlated, suggesting that TA, SS and firmness can be used as predictors of consumer preferences.     

仿刺参性腺酶解过程风味变化

生物酶解是提高水产品蛋白质利用率的有效手段，且酶解过程往往伴随肽类、氨基酸、小分子挥发性成分等的生成或反应，进而引起酶解液风味变化。仿刺参(Apostichopus japonicus)性腺富含蛋白质和多种功效成分，具有良好的开发利用前景。为探究仿刺参性腺酶解过程中蛋白质和风味的变化规律，采用中性蛋白酶对其进行酶解，对酶解过程中可溶性蛋白质、氨基酸态氮、游离氨基酸组成、挥发性成分的变化情况进行了检测分析。结果显示，仿刺参性腺匀浆液中可溶性蛋白质和氨基酸态氮的初始含量分别为1.14和0.15 g/100 g，可溶性蛋白质在酶解前30 min内迅速增加，之后基本保持不变，氨基酸态氮含量在前90 min内随时间延长而逐渐增加，90 min后略有下降，90 min时水解度最大，达43.66%。随着酶解时间的延长，酶解液的鲜味有所增强，腥味减弱，甜味和苦味也略有增强。酶解后游离氨基酸含量显著增加(P<0.05)，其中，呈鲜味的谷氨酸含量最高，其次为呈甜味的甘氨酸和丙氨酸。仿刺参性腺酶解过程气味发生明显变化，烃类种类和相对含量均明显增加，二甲基硫醚含量显著降低，这可能是酶解液腥味减弱的主要原因     

UV-C light inactivation kinetics of Penicillium expansum on pear surfaces: Influence on physicochemical and sensory quality during storage

UV-C inactivation kinetic data of Penicillium expansum on intact and wounded pear disks were determined. P. expansum conidia (0.5 mL, 1.6 × 10⁷ CFU/mL) were spot inoculated onto intact and wounded pear tissue with skin (excised disks), treated with UV-C doses ranging 0.101–3.06 kJ/m² at 23 °C and surviving conidia were enumerated. Changes in selected physicochemical parameters and sensory quality following UV-C treatment of whole pears were determined immediately after treatment, and 4 and 8 weeks of storage at 4 °C. A greater UV-C intensity was required for similar inactivation levels of P. expansum populations on wounded pear disks (3.1 kJ/m² for 2.7 log reduction) compared to intact pear disks (1.7 kJ/m² for 2.8 log reduction). No significant difference in % weight loss, or soluble solids content and texture was observed between UV-C treated and untreated pears. However, browning was observed on UV-C treated pear surfaces after 4 and 8 weeks along with changes in flavor and texture. An increase in consumer preference was noticed for the untreated control pears after 4 weeks storage.     

Effects of carboxymethyl cellulose and chitosan bilayer edible coating on postharvest quality of citrus fruit

There is increasing public interest in development of edible natural biodegradable coatings to replace the currently used commercial synthetic waxes for maintaining postharvest quality of citrus fruit. We tested the efficacy of a newly developed polysaccharide-based edible bilayer coating comprising carboxymethyl cellulose (CMC) and chitosan in preserving postharvest quality of various citrus fruit, including ‘Or’ and ‘Mor’ mandarins, ‘Navel’ oranges, and ‘Star Ruby’ grapefruit after simulated storage and marketing. In all citrus species, it was found that the CMC/chitosan bilayer coating was equally effective as the commercial polyethylene wax in enhancing fruit gloss. Furthermore, the CMC/chitosan bilayer coating slightly increased fruit firmness, especially of oranges and grapefruit, but was mostly not effective in preventing post-storage weight loss. Both the CMC/chitosan bilayer coating and the commercial wax had no significant effects on juice total soluble solids and acidity levels, and had similar effects on gas permeability, as indicated by only slight increases in internal CO₂ levels and in juice ethanol accumulation after storage. Sensory analyses revealed that neither the CMC/chitosan bilayer coating nor the commercial wax coating had any deleterious effects on flavor preference of ‘Navel’ orange and ‘Star Ruby’ grapefruit. However, application of the commercial wax, and moreover the CMC/chitosan bilayer coating, resulted in a gradual decrease in flavor acceptability of ‘Or’ and ‘Mor’ mandarins because of increased perception of off-flavors. Overall, we showed that the CMC/chitosan bilayer edible coating sufficiently enhanced fruit gloss, but was not effective in preventing postharvest weight loss. Furthermore, flavor quality was slightly impaired in mandarins but not in oranges and grapefruit.