HS-SPME/GC-MS测定石榴酒中香气组分的条件优化

该文使用气相质谱联用仪(gas chromatography-mass spectrometry,GC-MS)对石榴酒中的香气成分分析,在进样前对萃取纤维的种类,萃取的样品量,萃取时间,萃取温度4个条件进行优化,以期得到所测定的香气分子较多,重现性较好的GC-MS结果。试验结果表明对5.0 mL石榴酒样品,选取二乙烯基苯/碳分子筛/聚二甲基硅氧烷(divinylbenzene/carbon molecular sieve/dimethicone,DVB/CAR/PDMS)萃取纤维在45.0℃下萃取50 min,能够得到最优且重现性较好的GC-MS分析结果,定性出57种化合物,包括酯类、醇类、酸类、芳香族化合物等。为石榴酒的后续研究提供了基础。     

Physico-Chemical,antioxidant activities,textural, and sensory properties of yoghurt fortified with different states and rates of pomegranate seeds (Punica granatum L.)

This study examines the effects of incorporating fresh, frozen, osmodehydrated, and dried pomegranate seeds, at different concentrations (5, 10, and 20%) on the physicochemical, antioxidant, textural, and sensory properties of yoghurt. Antioxidant activity, pH, acidity, syneresis, and color of yoghurt were also evaluated during the storage (28 days) at 4°C. The principal component analysis (PCA) was performed to assess the correlations between different yoghurt formulation and their sensory attributes. Data showed that the addition of pomegranate seeds reduced pH and modified the chromatics coordinate (L*, a*, b*, C*, h°) and firmness of the yoghurt samples. In addition, acidity, °Brix, and syneresis increased compared to the control. Thanks to their high anthocyanin content, pomegranate seeds considerably improved the antioxidant activity essentially for yoghurt enriched with frozen seeds. In addition, the supplementation of 20% of frozen seeds into yoghurt was the most appreciated by panelists and improved the sensory properties in comparison to other formulation. According to PCA, taste and appearance were the main criteria for the overall acceptability of yoghurt. After 28 days of storage, the reddish color was reinforced; however, the antioxidant activity of yoghurts was reduced. Overall, it can be concluded that pomegranate seeds can be used as a natural ingredient to develop a novel yoghurt with high nutritional properties.     

石榴皮提取物在油田水处理中的应用研究

结合陕西丰富的林果资源,开展石榴皮提取物在油田采出水处理中的应用研究。采用失重法和动电位极化曲线研究了石榴皮提取物在1mol/L HCl溶液中对A3钢的缓蚀作用和对油田细菌的杀菌作用。结果显示石榴皮的提取物有较好的缓蚀作用,极化曲线表明其为混合抑制型缓蚀剂;对硫酸盐还原菌也有较好的杀菌作用,而对于腐生菌和铁细菌的杀菌作用较弱。     

Evaluation of Dyeing Properties of Carpet Woolen Yarn with Natural and Wild Pomegranate Peel (Punica granatum)

Natural and wild pomegranate peel have been used as colorants for wool yarn because of their high tannin contents. The woolen yarns dyed with pomegranate peel showed different shades of yellow and brown. Wild pomegranate peel has been used traditionally for dyeing wool to obtain brown and darker shades. Both natural and wild pomegranate peel were applied on woolen yarn in presence of four different mordants. Good light fastness was observed in dyed yarns that is due to the formation of complex with the metal which protects the chromophore from photolytic degradation. The values of washing fastness of the dyed samples show very good grades but the rubbing fastness in dyed yarns with wild pomegranate rind are not so good. Therefore, the dyeing potential of wild pomegranate peel as a natural source for wool yarn dyeing is considerable.     

石榴榨汁方法及其护色工艺研究

石榴的榨汁和护色在石榴汁生产过程中是很重要的工序,直接影响出汁率和产品的品质。对石榴的榨汁和护色方法进行研究表明,剥皮压榨石榴的出汁率和品质明显高于带皮压榨石榴,复合护色剂的护色效果高于单一护色剂,复合护色剂的最佳添加量为0.4g/100g柠檬酸和0.01g/100gVc,石榴汁自然澄清最佳时间为3h。     

Supplementation effects of pomegranate by-products on oxidative status,metabolic profile,and performance in transition dairy cows

Recent studies demonstrated a high antioxidant capacity for pomegranate components due to their rich bioactive compounds, such as conjugated fatty acids and phenolics. The objective of the present study was, therefore, to assess whether pomegranate seed or pomegranate seed pulp (peel + seed) supplementation could be effective to improve antioxidant status, and hence metabolic profile and performance in periparturient dairy cows. After a 1-wk pretreatment period, Holstein cows (primiparous n = 12, multiparous n = 18) were assigned to 3 dietary treatments from 25 d before expected calving through 25 d postcalving. The dietary treatments included (1) control (CON); (2) diet supplemented with pomegranate seeds (PS; 400 g/cow per day); and (3) diet supplemented with pomegranate seed pulp (PSP; 400 g of seeds/cow per day + 1200 g of peels/cow per day). Compared with CON, supplementation with either PS or PSP had no effects on dry matter intake, rumen fermentation, and plasma concentrations of cholesterol, total protein, globulin, and aspartate amino transferase, but enhanced plasma total antioxidant activity, and lowered triacylglycerol, free fatty acids (FFA), and β-hydroxybutyrate at both pre- and postpartum periods. Plasma concentration of glucose, albumin, malondialdehyde (MDA) and blood superoxide dismutase (SOD) activity were not affected by dietary treatments at prepartum, whereas SOD activity increased and glucose, albumin, MDA, and FFA-to-albumin ratio decreased by feeding both by-products at postpartum period. In contrast to PS, supplementing PSP resulted in a greater decrease in plasma glucose and triacylglycerol concentration and higher increase in SOD activity. Energy- and fat-corrected milk yields were higher in cows fed PSP diet compared with those fed CON or PS diets, but content of milk fat, protein, and lactose were similar across the dietary treatments. These findings indicated that dietary pomegranate by-products supplementation, in particular PSP, could improve antioxidant status, which was associated with a decline in lipid oxidation (FFA and β-hydroxybutyrate) and peroxidation (MDA) and an enhancement in glucose utilization as well as fat-corrected milk yield.     

响应面优化超临界CO2萃取怀远石榴籽油及其体外抗氧化性研究

以怀远石榴籽为原料,采用超临界CO_2萃取法制得石榴籽油。在单因素实验的基础上,以萃取压力、萃取温度、萃取时间及粉碎度为自变量,石榴籽油得率为响应值,采用响应面法优化萃取工艺,并对石榴籽油的理化指标与体外抗氧化性进行测定和分析。结果表明:超临界CO_2萃取石榴籽油的最佳萃取工艺条件为萃取压力32.0 MPa、萃取温度50.0℃、萃取时间103.0 min、粉碎度60.0目,在此条件下怀远石榴籽油得率为19.4%;超临界CO_2萃取法得到的石榴籽油酸值低,过氧化值与皂化值小,对DPPH·、ABTS~+·以及O_2~-·等自由基的清除能力较强。     

新疆石榴花多酚的提取工艺

采用单因素和正交试验,考察提取溶剂、提取时间、提取温度、料液比等因素对石榴花多酚提取的影响。结果显示：石榴花中多酚的最佳提取条件为以体积分数60% 乙醇作溶剂、料液比1:20(g/mL)、温度50℃、提取时间1h;在该优化条件下提取,多酚粗提物的得率为44.20%、纯度46.19%,即石榴花多酚得率达到20.42%。该方法操作简便、成本低、提取效果好,适合于工业化大生产。