蚕蛹油制备技术及其α-亚麻酸富集工艺研究进展

综述了蚕蛹油的提取技术现状和对蚕蛹油中α-亚麻酸富集纯化工艺及微胶囊化工艺方面的研究进展,为利用蚕蛹油开发α-亚麻酸功能产品提供参考.     

正己烷浸提法提取蚕蛹油工艺的优化研究

蚕蛹油是以蚕蛹体为原料抽取的油脂,含有多种饱和脂肪酸和不饱和脂肪酸,用途广泛。以缫丝后的干蚕蛹为原料,采用浸提法以正己烷为提取溶剂,利用单因素试验结合正交试验,对蚕蛹油的提取条件进行了优化。试验结果表明:正己烷提取蚕蛹油的最佳条件为提取温度40℃、提取时间3 h、料液质量浓度1∶6 g/m L、振荡速率160 r/min,蚕蛹油的出油率达到25.96%。     

蚕蛹资源的开发利用研究

利用蚕蛹开发高附加值的食、药用产品是蚕桑资源多元化利用及现代蚕桑产业发展的重要内容之一。近10多年,蚕蛹的利用范围不断拓展,利用形式从直接作为食品延伸到目标营养成分和活性成分的功能化利用,与此相应,蚕蛹深度开发利用的基础理论、加工技术、产品的营养保健功效研究也较为系统、全面地展开,该领域的研究涉及生物学、生物化学、分析化学、营养学、药理学以及先进的加工技术等。本文综述蚕蛹营养价值研究,蚕蛹蛋白、蚕蛹油和甲壳素的深加工技术及产品的功能与应用研究,蚕蛹虫草的栽培与药效成分和保健功效研究等方面取得的重要成果和进展,并对蚕蛹高附加值开发利用研究及产业的发展提出建议。     

蚕蛹油成分及提取工艺研究进展

蚕蛹油脂含量丰富,具有多种药理作用。介绍了超临界CO2萃取蚕蛹油,并进一步提取不饱和脂肪酸以及α-亚麻酸的工艺研究概况。蚕蛹油功能性成分提取工艺的改进,对蚕蛹综合利用具有重要意义。     

蚕蛹油脂提取方法及其功效研究进展

蚕蛹油富含脂肪酸,尤其是油酸、亚油酸和亚麻酸等多种人体自身不能合成的必需不饱和脂肪酸,具有极高的营养价值和保健功效。本文介绍了压榨法、浸出法等蚕蛹油提取方法,从提取时间、出油效率、溶剂残留等方面对这些方法进行了比较,综述了蚕蛹油的药用研究进展以及蚕蛹油在降血脂、降血糖、抗氧化等方面的保健功效。     

用有机溶剂提取栗蚕蛹油的工艺条件优化及蛹油成分分析

为高效开发利用栗蚕(Dictyoploca japonica)资源,以栗蚕蛹为原料,采用有机溶剂浸提法提取栗蚕蛹油,分析有机溶剂种类、原料粒度、原料质量浓度、提取温度、提取时间对提取得率的影响,确定了以石油醚为提取剂,原料粒度40目、原料质量浓度50 g/L、提取温度40℃、提取时间2.5 h为栗蚕蛹油提取的最佳条件。此条件下提取的栗蚕蛹油为淡黄色粘稠状液体,蛹油提取得率为26.01%。对抽提蛹油成分及其质量分数的检测结果为:水分0.52%,灰分0.64%,蛋白质0.40%,脂肪91.67%,粗纤维0.46%。     

超临界CO_2萃取及分子蒸馏技术提取缫丝蚕蛹油

采用超临界CO2及分子蒸馏技术萃取和精制缫丝蚕蛹油。经研究发现超临界CO2最佳提取工艺为投料360g,萃取温度45℃,萃取压力25MPa,萃取时间3h;分子蒸馏方面,经180℃蒸馏出黄色捎带黑的固体馏分后,缫丝蚕蛹油较澄清,颜色浅黄色,具有蚕蛹的香味。     

蚕蛹油脂的提取技术及营养与保健功能研究概况

有关蚕蛹油脂的提取技术及营养与保健功能研究已广泛开展。应用较多的蚕蛹油脂的分离提取方法是工艺简单、生产成本低的浸提法;新建立的超临界CO_2萃取、微波萃取和超声波辅助提取等技术使蚕蛹油脂的得率和纯度明显提高;酶法提取则具有成本低、环保、高效等特点。蚕蛹油脂富含油酸、亚油酸和α-亚麻酸等多种人体必需的不饱和脂肪酸,这些不饱和脂肪酸作为细胞膜和生物酶的基础成分,在维持机体正常生理代谢和对疾病预防的过程中发挥重要作用,具有辅助降血脂、降血糖、改善记忆、提高抗氧化能力、预防脂肪肝和抗血栓等多种保健功效,因而极具开发利用价值。本文概述上述研究领域的重要进展,并简要探讨蚕蛹油脂加工利用方面亟待解决与突破的关键技术问题。     

蚕蛹油微胶囊的制备

为了改善蚕蛹油的加工性能和延长其保质期,以大豆蛋白和β-环状糊精为壁材,采用喷雾干燥法制备蚕蛹油微胶囊。依据蚕蛹油微胶囊乳状液的稳定性检测指标,确定壁材大豆蛋白和β-环状糊精的质量比为1∶1。通过正交试验确定制备蚕蛹油微胶囊的最佳工艺条件为:芯材(蚕蛹油)与壁材的质量比为1∶2,乳状液中固形物的质量分数为20%,均质压力25MPa,喷雾干燥的进风温度190℃。在此工艺条件下制备蚕蛹油微胶囊的包埋率为91.2%。     

也谈蚕蛹油的开发利用

蚕蛹油是从蚕蛹中提炼出来的一种合有多种高级脂肪酸甘油脂的混合物,对人体具有多种生理保健功能。就蚕蛹油的提取方法,化学成分及组成,营养保健功能以及应用等方面的研究进行论述。     

Isolation and Culture of Ovine and Bubaline Small and Large Pre-antral Follicles: Effect of Cyclicity and Presence of a Dominant Follicle

Studies were conducted to examine the effects of the cyclicity and the presence of a dominant follicle (DF) in ovary on the recovery and in vitro growth of pre-antral follicles (PFs) in sheep and buffalo. Small pre-antral follicles (SPFs, 100–250 μm) and large pre-antral follicles (LPFs, 250–450 μm) were isolated from slaughterhouse ovaries in the breeding seasons by a mechanical and enzymatic method. The sheep and buffalo PFs were cultured in vitro for 6 and 15 days, respectively, and examined for their growth, survival and antrum formation rates and growth rates of oocytes in cultured pre-antral follicles. The follicles of the sheep and buffalo were recovered and cultured simultaneously within replicates. The recovery rates (number per ovary) of both SPFs and LPFs were significantly (p < 0.05) higher in cyclic ewes (SPFs: 22.0 ± 3.3 vs 12.1 ± 2.6 and LPFs: 16.0 ± 3.6 vs 9.2 ± 1.8) and buffaloes (SPFs: 9.2 ± 1.3 vs 4.1 ± 1.0 and LPFs: 10.3 ± 2.7 vs 5.4 ± 0.7) compared with those recovered from acyclic ones. Presence of a DF in ovary significantly (p < 0.05) reduced the recovery rates of LPFs in ewes (9.06 ± 2.7 vs 16.4 ± 3.8) but had no effect in buffalo. Cyclicity of animals or follicular dominance had no effects on in vitro growth, survival and antrum formation rates and growth rates of oocytes in cultured PFs of SPFs and LPFs in both sheep and buffalo. The in vitro growth, survival and antrum formation rates of LPFs and growth rates of oocytes in cultured LPFs were significantly (p < 0.05) higher than those observed in SPFs in both sheep and buffalo. The overall recovery and growth rates of the PFs were lower in buffaloes compared with ewes.     

Control of reproduction and of undesirable social and sexual behaviour in dogs and cats

Delmadinone acetate (DMA)? was tested by oral or parenteral administration to forty female and ten male dogs, and to twenty female and ten male cats for the control of heat and ovulation, and suppression of undesirable sexual and social behaviour. The indications, particulars of medication and the results obtained are shown in the table. The mode of action on the hypothalamus, pituitary and target organs is discussed. Over a thirty-six month trial period DMA proved to be a safe and efficacious drug for the control of sexual and related social functions in female and male pet animals. There were indications that even lower dosages than those employed may prove to be equally effective. Résumé. De l'acétate de delmadinone a été soumis à des tests, par administration buccale ou parentérale, sur quarante chiens femelles et dix chiens mâles et sur vingts chats femelles et dix chats mâles, pour le contrôle du rut et de l'ovulation et pour la suppression de comportement indésirable, sexuel et social. Les indications, les détails de médication et les résultats obtenus sont indiqués à la table. On discute du mode d'action sur Phypothalamus, l'hypophyse et les organes-cibles. Au cours d'une période d'essai de 36 mois, l'acétate de delmadinone s'est révelé une drogue éfficace, sans danger, pour le contrôle des fonctions sexuelles et sociales apparentées, chez les animaux familiers femelles et mâles. Il y avaient certaines indications, que même des doses plus faibles que celles utilisées peuvent se montrer également éffectives. Zusammenfassung. Delmadinonazetat (DMA) wurde durch orale oder parenterale Vera-breichung an vierzig weibliche und zehn männliche Hiade und an zwanzig weibliche und zehn männliche Katzen zur Kontrolle der Hitze und Ovulation, und Suppression von unerwünschtem sexuellem und sozialem Verhalten, gegeben. Die Indikationen, Eigenheiten von Medikation und die erlangten Ergebnisse sind in der Tabelle verzeichnet. Die Art der Wirkung auf den Hypo-thalamus, die Hypophyse und die Erfolgsorgane ist erört. Über eine 36 monatige Versuchsperiode, DMA bewies sich als ein sicheres und wirksames Medikament zur Kontrolle von sexuellen und verbundenen sozialen Funktionen in weiblichen und männlichen Haustieren. Es gab Anzeichen, dass selbst eine niedrigere Dosis als die angewand, sich ebenso wirksam erweisen mag.     

中国伞形科当归属及相关类群毛状体和果实结构的系统学价值

深入研究了当归属及其相关7属,古当归属,高山芹属,柳叶芹属,独活属,欧当归属,山芹属及前胡属毛状体和果实结构。结果显示毛状体及果实结构(如:毛状体细胞,翅,油管,维管束,中果皮,内果皮,结合面及结晶)可以用于区分当归属及其相关类群。滇南当归及隆萼当归应从当归属移入独活属,其余当归属物种分为结合面宽及结合面窄两组,前者与前胡属较为相似,但与独活属差别较大,后者与古当归属,高山芹属,柳叶芹属,欧当归属有相似之处。支持分子系统学揭示的当归属不是个自然类群,当归属与前胡属共同位于当归分支,而独活属位于独活分支。山芹属果实结构与其他属不同,翅的中果皮无细胞,且伴生油管位于维管束内侧,为分子系统学显示此属与高山芹属,柳叶芹属,及欧当归属亲缘关系较远提供了形态学依据。     

Absorption and metabolism of estrogens from the stomach and duodenum of pigs

To determine the absorption and metabolism of 17β-estradiol (E₂) by the stomach and liver of the pig, crystalline E₂ was placed in the stomach of prepubertal gilts. Blood samples were subsequently obtained from the hepatic portal and jugular veins and plasma was assayed for E₂, estrone (E₁), 17β-estradiol-glucuronide (E₂G), estrone-glucuronide (E₁G) and estrone-sulfate (E₁S). Concentrations of E₂, E₁, E₂G and E₁S rose in the hepatic portal vein within five min and remained elevated for several hr. Concentration of E₂ represented only 6% of the total estrogen detected in the hepatic portal vein during the sampling period, indicating that most of the E₂ was converted or conjugated prior to entering the hepatic portal vein. The metabolism of E₂ presumably occurred in the stomach mucosa because food had been withheld for 26 hr before infusion of E₂. Concentrations of E₂G, E₁G and E₁S, but not E₂ and E₁, rose in the jugular vein and remained elevated for several hr. The lack of a rise in E₂ and E₁ in the jugular vein indicates that the E₂ and E₁ from the hepatic portal vein were completely converted and/or removed by the liver. Most of E₂ was converted to E₁ and then to E₁G. The infusion of bile containing normal estrogens from pregnant gilts into the duodenum of prepubertal gilts resulted in a peak of E₁G and E₂G in the hepatic portal and jugular veins within a few minutes. This was followed in about 180 min by a second sustained rise. The first peak was essentially abolished by extracting E₁ and E₂ from the bile before infusion. The second peak failed to occur in gilts given antibiotics orally to reduce gut bacteria before infusion of bile.     

Influence of L-Carnitine on Performance and Ruminal and Blood Metabolites of Grazing Calves and Finishing Lambs

Three experiments were conducted to study the influence of level and type of L-carnitine (LC) on performance and rumiasl and plasma metabolites of weanling calves and finishing lambs. Weanling calves (84) grazing dormant dallisgrass-bermudagrass forage were fed a 20% CP supplement to provide 0, 0.5, 1, or 2 g of ruminally unprotected (RUP) LC per calf daily in Exp. 1. There was a linear increase (P=0.01) and cubic response (P=0.03) to RUP LC in growth rate and quadratic changes (P=0.01) in plasma ammonia N (PAN) and plasma urea N (PUN). In Exp. 2, 32 lambs were individually fed 14% CP diets containing 0, 50, 100, or 200 ppm RUP LC or ruminally protected (RP) LC in a 2 × 4 arrangement of treatments. Lambs gained BW faster (P=0.03) and more efficiently (P=0.07) as the LC level increased to 100 ppm and then declined at 200 ppm (quadratic response). Longissimus area decreased (P=0.03), and fat cover tended (P=0.15) to decline, at 50 and 100 ppm LC and increased at 200 ppm (linear and quadratic response). Ruminal ammonia N levels were reduced at 50 ppm LC but increased at greater LC levels (linear, quadratic, and cubic response, P=0.02). Plasma carnitine concentrations increased (P=0.01) as the dietary level of LC increased. Protected LC was more effective than RUP LC in increasing growth rate (P=0.06) and reducing PAN (P=0.1). In Exp. 3, 16 wether and 16 ewe lambs were individually fed corn-based or soybean hull-based diets with 0 or 100 ppm RP LC in a 2 × 2 arrangement of treatments. Lambs fed RP LC gained BW faster and more efficiently (P=0.04) than lambs that were not fed LC. Lambs fed corn-based and soybean hull-based diets responded similarly to RP LC; however, performance was greater (P=0.03) for lambs fed the corn-based diet. Gender of lambs did not influence the response to diet or RP LC. Supplementing the diet with 100 ppm RP LC reduced (P=0.01) ruminal pH and ammonia N. Plasma carnitine concentrations were increased (P=0.01), and PAN was decreased (P=0.04) by feeding 100 ppm RP LC. Ruminnaly unprotected and RP LC were effective in improving growth rate in ruminants; the latter appeared to be more effective in finishing lambs. L-carnitine reduced ruminal ammonia N and plasma glucose and, in some cases, PAN and PUN.     

Variation in quantity and quality of native forages and grazing behavior of cattle and goats in Tanzania

The study was conducted to assess the effects of seasonal variation in the quality and quantity of pasture and management of livestock exclosures (ngitili) on the grazing behavior of cattle and goats. The study was 2×2×2 factorial design with three independent variables: season (Dry or Rainy), ngitili management (Private or Communal) and animal species (Cattle or Goats). Focal and scan observation methods were used to record different behavioral activities. Vegetation attributes from the study areas were measured in two consecutive seasons. Most key forage species had significant higher crude protein (CP) content and in vitro organic matter digestibility (INVOMD) in rainy than in dry season (P<0.05), but Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) did not vary significantly with season (P>0.05). ADF and NDF were significantly higher in species from communal ngitili than those from private ngitili (P<0.05). Above-ground herbaceous biomass and bulk density (BD) were significantly higher in the rainy season and in the private ngitili than in the dry season and in the communal ngitili respectively. Cattle and goats spent considerably more time grazing and browsing respectively in the rainy season than in the dry season (P<0.05). Cattle foraging activities did not vary significantly (P>0.05) with ngitili management, but goats found to spend considerably more time browsing in the communal ngitili and more time grazing in the private ngitili (P<0.05). Despite the merits of stocking cattle and goats together in the heterogeneous pasture, seasonal variation in forage resources requires investigation of other strategies such as use of multipurpose trees and treatment of crop residues to improve livestock production.     

Determination and Occurrence of Free and Conjugated Histamine in Urine of Sheep

1. By modifying the method of Duriér & Pernow (1956) the urinary excretion of free and conjugated histamine was examined in 11 healthy adult sheep.
2. The mean excretion of free histamine was 9.8 ± 9.0 (s) µg base/24 hrs. (uncorrected for losses during extraction). When individual means were used, the range was: 2.1–34.2 µg base/24 hrs. The intraindividual variations were of the same order as the interindividual variations.
3. The mean excretion of conjugated histamine was equivalent to 15.1 ± 9.9 (s) µg histamine base/24 hrs. In all animals the ratio conjugated/free histamine was above 1. The interindividual as well as the intraindividual variation for conjugated histamine was of the same order as for free histamine.

     

Effect of hybrid rice varieties on growth and development of broilers and ducks

Three experiments (Exp. 1, n = 144 broilers [Ross × Ross]; Exp. 2, n = 118 mallard ducklings [Anas platyrhynchos]; and Exp. 3, n = 75 mature mallard ducks) were conducted to determine the effects of 3 levels of unmilled hybrid rice on growth performance and organ and gastrointestinal tract development. The dietary treatments were 1) corn-soybean meal (basal), 2) basal + 5% hybrid rice, and 3) basal + 10% hybrid rice for Exp. 1 to 3, respectively. One bird from each pen in Exp. 1 (n = 24) and all the birds in Exp. 2 (n = 118) and Exp. 3 (n = 75) were randomly selected and euthanized to determine linear measurements and organ and gastrointestinal tract weight. In Exp. 1 and 2, birds fed 10% rice experienced slower growth (P < 0.05) than birds fed the basal diet. In Exp. 3, the addition of rice did not affect growth performance. Rice addition did not affect organ length or weight (P > 0.05) in Exp. 1. However, birds fed 5% rice had significantly increased (P < 0.05) pancreas, ileum, and jejunum weights in Exp. 2, and 10% rice significantly increased (P < 0.05) liver weight in Exp. 3. The addition of 10% unmilled rice to broiler and duck diets may reduce growth performance.     

Knowledge and prevention of tickborne diseases among Hispanic and non‐Hispanic residents of Maryland and Virginia

Tickborne diseases (TBDs) such as Lyme disease (LD), babesiosis, ehrlichiosis and Rocky Mountain spotted fever cause substantial morbidity and even mortality in the USA. Data indicate that Hispanic populations may be at greater risk for occupational exposure to ticks and disseminated LD; however, information on knowledge and practices of Hispanic populations regarding TBDs is limited. We surveyed 153 Hispanic and 153 non‐Hispanic residents of Maryland and Virginia to assess awareness of TBDs, prevention practices and risk of tick encounters. Hispanic respondents were less likely than non‐Hispanics to report familiarity with LD symptoms (21% vs. 53%, p < 0.001) and correctly identify ticks as vectors of LD (40% vs. 85%, p < 0.001). Although there was no significant difference in overall proportion of respondents who routinely take one or more preventive measures to prevent tick bites (59% vs. 61%, p = 0.65), Hispanics were more likely to report showering after coming indoors (36% vs. 25%, p = 0.04) but less likely to conduct daily tick checks compared with non‐Hispanics (17% vs. 35%, p < 0.001). History of tick bite or finding a tick crawling on oneself or a household member in the past year did not significantly differ between Hispanics and non‐Hispanics (19% vs. 24%, p = 0.26). Notably, after controlling for Hispanic/non‐Hispanic ethnicity, primary language (English vs. Spanish) was a significant predictor of whether an individual had knowledge of LD symptoms, correctly identified ticks as vectors for LD and performed daily tick checks. These results provide guidance for future development of more targeted and effective TBD prevention education for both Hispanic and non‐Hispanic communities.     

猪圆环病毒与胸膜肺炎放线杆菌混合感染的诊治

2019年3月,大庆某规模化猪场个别猪出现发育不良、咳喘、消瘦、皮肤苍白和呼吸困难等症状,随后出现死亡。为明确发病原因,降低损失,对送检病死猪进行临床症状观察、剖检及实验室检测,并对病原菌进行药物敏感性试验。检测结果为致病性胸膜肺炎放线杆菌和猪圆环病毒混合感染所致,分离的胸膜肺炎放线杆菌对阿莫西林和头孢唑高度敏感。本研究为养殖场饲养猪的死亡病因分析和防治提供了参考。