密集烘烤时的温湿条件对烤后烟叶类胡萝卜素及其降解产物含量的影响

[目的]研究密集烘烤时的温湿度条件对烤后烟叶中类胡萝卜素及其降解产物的影响。[方法]以烤烟品种K326中部叶(第11～12位叶)为试验材料,电热式温湿自控密集烤烟箱进行烘烤,采用反相高效液相色谱法和内标法分别测定烤后烟叶类胡萝卜素及烟叶类胡萝卜素香气成分。[结果]试验表明,烤后烟叶中类胡萝卜素含量与β-胡萝卜素含量呈极显著正相关,二者含量与类胡萝卜素降解产物含量呈显著负相关。低温(干球温度36～38℃)中湿(相对湿度80%～85%)处理烤后的烟叶中类胡萝卜素的各组分中,β-胡萝卜素含量最低,叶黄素、新黄质和紫黄质含量最高,类胡萝卜素降解产物含量最多,从而影响烟叶的香气品质。[结论]研究可为优质特色烟叶生产烘烤工艺的优化提供参考。     

Improved fruit retention,yield and fruit quality in mango with exogenous application of polyamines

Aqueous solutions (0, 0.01, 0.1, 1 mM) of PAs (putrescine, spermine, spermidine) containing a surfactant ‘Tween 20’ were sprayed onto panicles of mango (Mangifera indica L. cv. Kensington Pride) at final fruit set (FFS) stage (when all flowers abscised but remain attached to the panicle) during 1999–2001 to investigate their effects on fruit retention, yield, size, and fruit quality. The optimum time of PA application for improving final fruit retention and fruit yield was determined by spraying different concentrations (0, 0.01, 0.1, 1 mM) of spermine (SPM) containing a surfactant ‘Tween 20’ at four phenological stages including flower bud differentiation (FBD), 5–8 cm long grown panicles (GP), full bloom (FB) and at initial fruit set (IFS) stage (when 2/3rd of the flowers were abscised but attached to the panicle) during 2000. Exogenous application of PAs at FFS stage did not significantly increase fruit retention. However, compared to control (0.79 and 2.3% fruit retention), PAs treatments resulted in comparatively higher mean fruit retention (1.53 and 2.92%) during 1999–2000 and 2000–2001, respectively. Among three PAs tested, SPM was more effective in increasing mean final fruit retention. Fruit size was not significantly affected by any PA treatment. Among the four application times, SPM (0.01 mM) spray at FB stage resulted in significantly (P ≤ 0.05) greater fruit retention (4.99%) compared with control (2.1%). However, fruit yield was comparatively higher with SPM (0.01 mM) application at IFS stage or 5–8 cm GP stage compared to the control. Overall FB application was found as the optimum time of application. Application of PAs at FFS stage retarded fruit skin colour development compared to the control. Sugars and total soluble solids (TSS) were generally reduced in PA-treated fruit. Fruit acidity was increased (16.7%) with SPM, whereas it was 11% with PUT treatment as compared to the control. Total carotenoids in pulp were generally improved (49%) with PA treatments, compared to the control. Ascorbic acid concentrations were significantly reduced with spermidine (SPD) (24%) and PUT (20%) treatments, whereas higher concentrations of SPM (1 mM) tended to increase it (12.7%) compared to the control. In conclusion, application of SPM (0.01 mM) at FB stage resulted in the highest fruit retention, whereas SPM (0.01) spray at GP or IFS stage resulted in higher fruit yield. PUT application at FFS stage significantly improved fruit quality by increasing total carotenoid, while reducing acid content of ripe fruit.     

Agronomic characteristics and carotenoid content of five Bola-type paprika red pepper (Capsicum annuum L.) cultivars

The production of sweet paprika in Spain uses exclusively fruit of Bola-type Capsicum annuum L. This work describes the evaluation of the agronomic behaviour of five new cultivars of the Bola-type paprika red pepper, selected in the Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA), and grown in Extremadura for 3 years. The colour and the pigment content of the paprika elaborated following the traditional procedure of La Vera were also studied.     

类胡萝卜素生物利用率及其乳液递送体系研究进展

工作环境与生活状态的改变导致人群亚健康状态以及人口老龄化问题已经引起人们的重视.具有多重生物活性的膳食补充剂对人体健康有多种保护功能,已经成为消费者与研究者共同关注的热点.类胡萝卜素不仅是光合生物中发挥关键活性的天然色素,也常被用作营养补充剂应用于食品工业、制药行业中.然而类胡萝卜素对加工生产条件、环境因素的高敏感性与...     

植物类胡萝卜素生物合成及其调控与遗传操作

类胡萝卜素是生物体内通过类异戊二烯途径合成的、自然界广泛存在的一大类天然色素物质的总称。近年来,类胡萝卜素生物合成基因的分离和功能鉴定与有关类胡萝卜素生物合成调控机制研究的新进展,使通过遗传操作调控植物体内类胡萝卜素生物合成途径成为可能。本文主要综述了近年来类胡萝卜素生物合成及其调控研究的进展,并介绍了应用转基因技术改变植物体内类胡萝卜素成分与含量的成功事例。     

茶类胡萝卜素的高效液相色谱测定法

应用高效液相色谱法，研究分离测定茶类胡萝卜素的结果表明：采用己烷∶丙酮∶乙醇∶甲苯（１０∶７∶６∶７）与４０％甲醇氢氧化钾浸提皂化１２ｈ制备样品，使用Ｎｏｖａ－ＰａｋＣ１８不锈钢柱（３．９×１５０ｍｍ），乙腈∶三氯甲烷∶叔丁醇（８３∶１５∶２）作流动相，流量线性梯度洗脱，柱温２５℃等色谱条件，在４４０ｎｍ波长下检测，使茶叶中的４种主要类胡萝卜素（β－胡萝卜素，叶黄质，堇黄质，新黄质）在１０ｍｉｎ内得到了较好的分离。其分辨率高，分析时间短，重现性与线性关系良好，适合于大量试样的分析。     

Utilization of carotenoids from various sources by rainbow trout: muscle colour,carotenoid digestibility and retention

Rainbow trout (Oncorhynchus mykiss) with a mean (sd) weight of 120 (2) g were fed diets supplemented with astaxanthin extracted from the yeast Phaffia rhodozyma (OY1 = 50 mg carotenoids kg^–1 feed, OY2 = 100 mg carotenoids kg^–1 feed), astaxanthin (AX = 100 mg astaxanthin kg^–1 feed) and canthaxanthin (CX = 100 mg canthaxanthin kg^–1 feed) for 4 weeks. Muscle analyses at the end of the experiment indicated a significantly higher carotenoid concentration in the AX group, while CX and OY1 groups were similar in spite of the differences in dietary concentration. The measure of total muscle colour difference (E^* _ab) between initial samples and 4 week ones was higher for the AX fish group but showed no significant difference between OY1, OY2, and CX. The hue and the reflectance ratio (R₆₅₀:R₅₁₀) of fish muscle increased in proportion to carotenoid intake. Digestibility (ADC) of yeast astaxanthin in OY1 and OY2 groups was significantly higher than that in the AX group. Canthaxanthin ADC was about one sixth of that of astaxanthin (AX group). Carotenoid retention in the muscle, expressed as a percentage of carotenoid intake, was higher for the AX group than that recorded for OY1 and OY2. According to ADC, carotenoid retention showed a marked lower value for the CX group. Muscle retentions were similar for astaxanthins from both sources.     

小麦品种(系)籽粒类胡萝卜素含量及其与其他品质性状的相关性

为给小麦类胡萝卜素及其他品质性状的品种资源筛选和品质改良提供参考,以黄淮麦区不同时期的31个小麦品种(系)为材料,探讨其全麦粉类胡萝卜素含量、脂肪氧化酶活性等品质性状的品种间差异及类胡萝卜素含量与其他品质性状的相关性。结果表明,类胡萝卜素含量、脂肪氧化酶活性、总戊聚糖、水溶性和非水溶性戊聚糖含量、色差仪参数、RVA参数、近红外参数等品质性状的品种间差异均达到显著水平;类胡萝卜素含量与水溶性戊聚糖含量、黄度呈极显著正相关,与高峰黏度、低谷黏度、稀懈值、最终黏度、容重和形成时间呈极显著负相关,与峰值时间、蛋白质含量和稳定时间呈显著负相关。根据供试品种(系)类胡萝卜素含量的聚类分析结果,孟0318等19个品种(系)聚为一类,洛麦23等10个品种(系)聚为一类,淮麦22和济麦22聚为一类,三个类别的类胡萝卜素含量平均值分别为1.93、1.07和2.99mg·kg-1。     

Whole grain phytochemicals and health

Phytochemicals and antioxidants in whole grains have not received as much attention as the phytochemicals in fruits and vegetables although the increased consumption of whole grains and whole grain products has been associated with reduced risk of developing chronic diseases such as cardiovascular disease, type 2 diabetes, some cancers and all-cause mortality. Recent research has shown that the total phytochemical content and antioxidant activity of whole grains have been commonly underestimated in the literature, and that whole grains contain more phytochemicals than was previously reported. Most whole grain phenolics are in bound form, 85% in corn, 76% in wheat, and 75% in oats. In addition, whole grains contain unique phytochemicals that complement those in fruits and vegetables when consumed together. The beneficial effects associated with whole grain consumption are in part due to the existence of the unique phytochemicals of whole grains. The majority of phytochemicals of whole grains that are beneficial for health are present in the bran/germ fraction. In whole wheat flour, the bran/germ fraction contributed 83% of total phenolic content, 79% of total flavonoid content, 78% of total zeaxanthin, 51% of total lutein, and 42% of total β-cryptoxanthin. The bran/germ fraction of whole wheat may therefore impart greater health benefits when consumed as part of a diet, and help reduce the risk of chronic diseases. This paper will review recent research on the phytochemicals and antioxidant activity of whole grains and their unique contribution to the health benefits of whole grains.