Dietary krill oil increases docosahexaenoic acid and reduces 2-arachidonoylglycerol but not N-acylethanolamine levels in the brain of obese Zucker rats

Evidence suggests that dietary long chain polyunsaturated fatty acids (LCPUFAs), and particularly those belonging to the n-3 family, may influence the brain fatty acid profile and, thereby, the biosynthesis of endocannabinoids in rodents. However, the doses used are usually quite high and not comparable with human intake. Recently, we have shown that relatively low doses of dietary n-3 LCPUFAs (4 weeks), in the form of either fish or krill oil, balanced for EPA and DHA content, and against a control diet with no EPA and DHA and similar contents of oleic, linoleic and α-linolenic acids, lower the concentrations of the endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), in the visceral adipose tissue, and of AEA in the liver and heart, of obese Zucker rats. This, in turn, is associated with lower levels of arachidonic acid in membrane phospholipids and with amelioration of some metabolic syndrome parameters. We investigated here whether in Zucker rats, under the same conditions, fish and krill oil are also able to influence LCPUFA and endocannabinoid profiles in brain. Only krill oil was able to increase significantly DHA levels in brain phospholipids, with no changes in arachidonic acid. DHA increase was associated with lower levels of 2-AG in the brain, whereas AEA and its congeners, N-palmitoylethanolamine and N-oleoylethanolamine, were unchanged. We conclude that, despite the strong impact of dietary n-3 fatty acid on endocannabinoid levels previously observed in peripheral tissues, in the brain only 2-AG is affected by dietary krill oil, suggesting that the beneficial effect of the latter on the metabolic syndrome is mostly exerted by modifying peripheral endocannabinoids. Nevertheless, possible effects of dietary krill oil in the brain through modification of 2-AG levels deserve further investigation.     

脯氨酰内肽酶水解啤酒蛋白的研究

将脯氨酰内肽酶(PEP)添加在啤酒后酵液中,通过冷混浊实验分析脯氨酰内肽酶对啤酒非生物稳定性的影响。结果表明,添加5mg/L的脯氨酰内肽酶就能有效地提高啤酒的非生物稳定性;采用75%硫酸铵沉淀啤酒蛋白,进行SDS-PAGE电泳分析,结果显示,啤酒蛋白电泳图谱的分布主要表现为8～14.4 ku的窄带和35～45 ku的宽带,而经脯氨酰内肽酶处理的啤酒蛋白电泳图谱中8～14.4 ku的条带消失,说明此蛋白被脯氨酰内肽酶水解。     

反油酸诱导人脐静脉内皮细胞转录组学及生物信息学分析

以反油酸诱导人脐静脉内皮细胞后,结合转录组学分析及其生物信息学分析,在转录水平上对相关差异表达基因进行研究。结果表明：共检测到95?条基因显著变化,其中31?条基因上调,64?条基因下调。并通过生物信息学分析,其中参与生物进程显著性差异表达基因共772?条,关于细胞组成的基因显著表达性差异基因共46?条,关于分子功能的基因显著表达性差异基因共122?条。共检测到93?条信号通路,其中显著变化的有11?条,其中包括萜类骨架生物合成通路、类固醇生物合成通路和脂肪酸代谢通路等。根据蛋白质基因互作通路图,重点分析了同时参与不同通路的靶基因,包括脂肪酸合成酶、STAT4转录因子及IL-23细胞因子等。     

全谷物发芽糙米韧性饼干制作工艺优化

为了拓展发芽糙米的利用途径,丰富全谷物食品种类,本文以发芽糙米粉替代部分小麦粉应用于饼干,开展了配方及焙烤工艺参数对韧性饼干品质特性的影响研究,优化了饼干的制作工艺.结果表明,随着发芽糙米粉的增加,饼干色泽降低,硬度呈上升趋势,延展度、感官评分均呈先增加后降低的趋势;增大黄油的添加量,延展度、膨松度变化较小;增大糖粉的...     

β-二氢大马酮的合成和加香作用研究

以β－紫罗兰酮为原料，经成肟、环化、还原脱氨，生成β－二氢大马酮。研制成功一种新的还原脱氨方法。对β－二氢大马酮在卷烟中的加香作用进行了初步研究。     

植物甜蛋白的研究进展

20世纪60年代人们陆续从热带植物中发现了六种天然甜蛋白(嗦吗甜，莫奈林，马槟榔蛋白，培它丁，仙茅蛋白，奇果蛋白)，介绍了几种甜蛋白的开发研究进展，以及甜蛋白的新进展及应用前景.     

Pigments profile in monovarietal virgin olive oils from various Italian olive varieties

This paper presents the investigation of the chlorophyll and carotenoid pigments composition in monovarietal virgin olive oils produced from the five main olive varieties (Minuta, Ottobratica, Calabrese, Ogliarola, Baddarica) cultivated in Sicily (southern Italy), from four main olive varieties (DolceAgogia, Moraiolo, Leccino, Frantoio) cultivated in Umbria (central Italy), and from three main olive varieties (Leccino, Oliva Nera di Collecorto, Noccioluta) cultivated in Molise (central Italy). Reversed-phase high performance liquid chromatography using a C-30 column with photodiode array detection was used for pigments analyses. In all, 19 compounds were identified and quantified in 60 olive oils samples. The qualitative pigments pattern was similar among the varieties investigated, whereas quantitative differences were found among the different cultivars; among the varieties investigated in this work, the oils from Umbria showed the highest pigment content (34.19 ppm in average), followed by the oils from Molise (18.61 ppm in average) and the oils from Sicily which showed the lowest pigment contents (13.38 ppm in average). In general, pheophytin a was the major component (range 0.49–19.42 ppm), followed by β-carotene (range 1.27–9.30 ppm) and lutein (range 0.44–5.12 ppm). Those differences may be due to genetic factors and/or geographical differences. Moreover, auroxanthin was detected for the first time in olive oils and was detected only in olive oils from Umbria and Molise regions. The ratio between the two isochromic pigment fractions, namely the ratio between the chlorophyll and carotenoid fractions showed an average value close to unity. The lutein/β-carotene ratio was less than one in the majority of the cases. These parameters, along with other analytical parameters, could be used as indicators of typicality in olive oils. The presence of a specific pigment profile in olive oils could infact be used to guarantee the genuineness of the product, since the quality control of food requires a precise knowledge of the pigments composition of the original products.     

Identification of aroma-active compounds in ‘wonderful’ pomegranate fruit using solvent-assisted flavour evaporation and headspace solid-phase micro-extraction methods

During the last few years, there has been a tremendous increase in consumption of pomegranate fruit and juice. Nevertheless, very little is yet known regarding the volatile constituents that determine the unique aroma of pomegranate fruit. We extracted aroma volatiles from fresh ‘Wonderful’ pomegranate juice using solvent-assisted flavour evaporation (SAFE) and headspace solid-phase micro-extraction (HS-SPME) methods, and applied gas chromatography–olfactometry (GC–O) (‘sniffing’) combined with gas chromatography–mass spectrometry (GC–MS) analysis, in order to identify volatile aroma-active compounds. In addition, we performed stir bar sorptive extraction (SBSE) of pomegranate aroma volatiles, coupled with GC–MS analysis, in order to assist in identifying aroma-active compounds. Overall, we tentatively identified 23 volatiles in the SAFE and HS-SPME extracts; they belonged to various chemical classes, including aldehydes, terpenes, alcohols, esters, furans and acids. Using the GC–O nasal impact frequency method, we tentatively detected 12 aroma-active peaks and identified the corresponding odourants by GC–MS. The aroma-active compounds of ‘Wonderful’ pomegranates were ethyl-2-methylbutanoate (fruity, apple), hexanal (green), β-pinene (pine, herbal), β-myrecene (woody, musty), cis-3-hexenal (green), limonene (fruity, musty), cis-2-heptenal (soapy, mushroom), cis-3-hexenol (earthy, grassy), 2-ethylhexanol (floral), β-caryophyllene (fruity, musty), 2(5H)-furanone (sweet, fruity) and β-sesquiphellandrene (terpene, almond). Overall, the flavour of ‘Wonderful’ pomegranate fruit derives from a mixture of various ‘green’, ‘woody’, ‘earthy’, ‘fruity’, ‘floral’, ‘sweet’ and ‘musty’ notes.     

Application of near infrared spectroscopy for the rapid determination of antioxidant activity of bamboo leaf extract

This study was carried out to evaluate the feasibility of using near infrared (NIR) spectroscopy for determining three antioxidant activity indices of the extract of bamboo leaves (EBL), specifically 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP), and 2,2′-azinobis-(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS). Four different linear and nonlinear regressions tools (i.e. partial least squares (PLS), multiple linear regression (MLR), back-propagation artificial neural network (BP-ANN), and least squares support vector machine (LS-SVM)) were systemically studied and compared in developing the model. Variable selection was first time considered in applying the NIR spectroscopic technique for the determination of antioxidant activity of food or agricultural products. On the basis of these selected optimum wavelengths, the established MLR calibration models provided the coefficients of correlation with a prediction (r_pre) of 0.863, 0.910, and 0.966 for DPPH, FARP, and ABTS determinations, respectively. The overall results of this study revealed the potential for use of NIR spectroscopy as an objective and non-destructive method to inspect the antioxidant activity of EBL.     

Composition of meat and offal from weaned and fattened rabbits and results of stereospecific analysis of triacylglycerols and phosphatidylcholines

BACKGROUND: Rabbit meat has excellent nutritive properties. The purpose of this study was to characterize rabbit meat and offal; in particular, the lipid fraction was studied in order to evaluate total and positional fatty acid (FA) compositions of triacylglycerol (TAG) and phosphatidylcholine (PC) fractions. Eight samples of weaned and eight of fattened rabbits were considered. RESULTS: Fattened rabbit meat contained slightly higher protein percentage content (P < 0.05) in comparison to weaned (20.1% versus 18.0%). Calcium content was higher in meat than in offal, unlike sodium, iron, zinc, manganese and copper. The cholesterol content in offal was much higher than in meat. FA profiles of total lipid showed a high percentage of unsaturated fatty acids and an n‐6/n‐3 ratio of 10.3 for fattened rabbit meat. Stereospecific analysis of TAG and PC was carried out on an eight‐sample pool of each meat and offal from weaned and fattened rabbits. In all samples the sn‐2‐position was prevalently esterified with oleic and linoleic acids in TAG, with polyunsaturated fatty acids in PC. CONCLUSION: Lipids from rabbit meat presented higher content of monounsaturated FA and lower n‐6/n‐3 ratio in comparison to offal, which was characterized by higher cholesterol and mineral levels. Copyright © 2011 Society of Chemical Industry