Consumption of purple sweet potato leaves modulates human immune response: T-lymphocyte functions, lytic activity of natural killer cell and antibody production

AIM: To study the immunological effects of physiological doses of purple sweet potato leaves(PSPL). METHODS: The randomized crossover study(two periods, each lasting for 2 wk) involved 16 healthy non-smoking adults of normal weight. The 6-wk study consisted of a run-in(wk 1) PSPL diet(daily consumption of 200 g PSPL) or a control diet(low polyphenols, with the amount of carotenoids adjusted to the same level as that of PSPL)(wk 2-3), washout diet(wk 4), and switched diet(wk 5-6). Fasting blood was collected weekly in the morning. T-lymphocyte function was assessed via the proliferation and secretion of immunoreactive cytokines. Salivary IgA secretion and the specific cytotoxic activities of cytotoxic T lymphocytes and natural killer(NK) cells were determined. RESULTS: The plasma β-carotene level increased with time in both groups, while the plasma polyphenol level decreased in the control group, and no significant difference was detected between the two groups. Although plasma polyphenol levels did not significantly increase in the PSPL group at the end of the study, they were significantly elevated in urine. PSPL consumption produced a significant increase in proliferation responsiveness of peripheral blood mononuclear cells(PBMC) and their secretion of immunoreactive IL-2 and IL-4. As well, lytic activity in NK cells was elevated in a time-dependent fashion. Salivary IgA secretion significantly decreased in control group after 2 wk, and returned to baseline following dietary switch to PSPL. CONCLUSION: Consumption of PSPL modulates various immune functions including increased proliferation responsiveness of PBMC, secretion of cytokines IL-2 and IL-4, and the lytic activity of NK cells. The responsible determinants of PSPL remain to be elucidated, as does the biological significance of the present observations.

Coronatine Induces an Accumulation of Anthocyanin and Starch in Purple-fleshed Sweetpotato(Ipomoea batatas Lam.)

[Objective]The objective of this research was to examine the effects of COR on anthocyanin and starch content in storage roots of two PFS genotypes,and to explore the relationships between anthocyanin synthesis and starch accumulation.[Method]A field experiment was carried out to determine the changes in yield components,yield,contents of anthocyanin and starch,activities of phenylalanine ammonia-lyase(PAL)and adenosine 5-diphosphate glucose pyrophosphorylase(AGPase)in two genotypes of PFS(Ipomoea batatas L.,var.‘Ayamurasaki’and‘Jishu18’).[Result]The application of COR significantly increased starch and anthocyanin content in storage roots of Jishu18 across developmental stages by inducing the activities of PAL and AGPase,and finally enhanced yield by promoting fresh weight of storage roots.Ayamurasaki was insensitive to treatment with COR although its PAL activity temporally increased.The starch and anthocyanin content of Aya,and the anthocyanin content of Jishu18 increased progressively across developmental stages with or without COR application,but the starch content of Jishu18increased initially,then decreased before increasing again without application of COR.Treatment with COR reduced downward trend of starch accumulation in Jishu18.Thus,the effect of COR on accumulation of anthocyanin and starch in storage roots of PFS differs according to genotypes.[Conclusion]The application of0.05μmol/L COR may increase starch and anthocyanin content in PFS genotypes with lower starch and anthocyanin content in storage roots.

Regulation of Anthocyanin during Storage Root Development Stage in Sweet Potato(Ipomoea batatas(L.) Lam.)

Anthocyanin accumulation during storage root development in purple-fleshed sweet potato was analyzed by detection of anthocyanin concentration, accumulation rate and the expression pattern of anthocyanin biosynthetic genes by semi-quantitative RT-PCR. Anthocyanin concentration in sweet potato cvs Jishu 18 and Ayamurasaki increased steadily during storage root development stage. The accumulation rate in two genotypes peaked at 50 to 65 d after transplanting, and then declined rapidly. During storage root development of Ayamurasaki, the anthocyanin biosynthesis gene, IbCHS, was constitutively expressed, the genes IbF3H, IbDFR, IbANS were induced steadily, reaching a maximum at the later stage of root thickening, and IbPAL steadily decreased. Therefore, the mechanism of anthocyanin accumulation differed between the two cultivars, and anthocyanin biosynthesis was regulated through regulation of its synthetic enzymes.

Diacylated anthocyanins from purple sweet potato(Ipomoea batatas L.)attenuate hyperglycemia and hyperuricemia in mice induced by a high-fructose/high-fat diet

Studies have shown that targeting xanthine oxidase(XO)can be a feasible treatment for fructose-induced hyperuricemia and hyperglycemia.This study aimed to evaluate the dual regulatory effects and molecular mechanisms of diacylated anthocyanins from purple sweet potato(diacylated AF-PSPs)on hyperglycemia and hyperuricemia induced by a high-fructose/high-fat diet.The body weight,organ index,serum biochemical indexes,and liver antioxidant indexes of mice were measured,and the kidneys were observed in pathological sections.The relative expression levels of messenger RNAs(mRNAs)of fructose metabolism pathway enzymes in kidney were detected by fluorescent real-time quantitative polymerase chain(qPCR)reaction technique,and the expression of renal transporter protein and inflammatory factor pathway protein was determined by immunohistochemistry(IHC)technique.Results showed that diacylated AF-PSPs alleviated hyperuricemia in mice,and that this effect might be related to the regulation of liver XO activity,lipid accumulation,and relevant renal transporters.Diacylated AF-PSPs reduced body weight and relieved lipid metabolism disorder,liver lipid accumulation,and liver oxidative stress,thereby enhancing insulin utilization and sensitivity,lowering blood sugar,and reducing hyperglycemia in mice.Also,diacylated AF-PSPs restored mRNA levels related to renal fructose metabolism,and reduced kidney injury and inflammation.This study provided experimental evidence for the mechanisms of dual regulation of blood glucose and uric acid(UA)by diacylated AF-PSPs and their utilization as functional foods in the management of metabolic syndrome.

杂粮、糯小麦与普通小麦配粉对面团特性和面条品质的影响

杂粮面条具有很好的特色风味及营养保健功能,为拓宽糯小麦的应用范围,提高面条营养价值,利用两种杂粮粉(紫薯粉和苦荞粉)、两种筋力类型糯小麦粉与特一粉配粉,分析杂粮粉和糯小麦粉对面粉的理化特性及面条品质的影响。结果表明:糯小麦杂粮配粉及面条制作中,添加紫薯粉比添加苦荞粉总淀粉含量、稳定时间低,直链淀粉含量、吸水率和面条评分高;糯小麦比例提高,总淀粉含量升高,直链淀粉含量、面粉峰值粘度和回升值下降,面条评分增加;强筋糯小麦配粉更有利于杂粮面条品质改良,以30%扬糯麦2号和15%紫薯粉配粉,面条综合评分最高。

含紫薯花青素的槟榔芋淀粉薄膜性能及其应用

开发含紫薯花青素(PSPA)并可生物降解的槟榔芋淀粉薄膜(TSF),并研究其光学性能、厚度、含水率、水溶性、颜色、总酚含量、抗氧化活性、红外光谱和微观结构等性能,初步探讨TSF对鲜切莴笋、鱼肉和猪肉储存过程中新鲜度的指示作用。研究表明TSF的紫外-可见光谱和PSPA溶液的光谱变化规律是一致的,表明PSPA与槟榔芋淀粉具有良好的成膜机制。TSF厚度适中,含水率为39.17%,水溶性为36.93%;TSF的DPPH清除率达到94%,表明TSF的抗氧化活性高。将TSF应用于鲜切莴笋、鱼肉和猪肉的新鲜度监测,TSF先呈现淡紫色,随着时间推移,鲜切莴笋、鱼肉和猪肉逐渐腐败变质,48 h后,TSF在莴笋中呈现蓝紫色、猪肉中呈现浅绿色、鱼肉中呈现淡黄色。

紫薯香芋果冻的研制

以优质的紫薯和香芋为主要原料,经调配、混合熬煮、过滤、杀菌等工艺流程,研制出一种具有浓郁紫薯味和香芋味的果冻。以感官评价为评分标准,分析紫薯汁与香芋汁的配比,白砂糖、柠檬酸及复配胶的添加量对果冻品质的影响。通过正交试验确定紫薯香芋果冻的最佳配方。结果表明,影响果冻感官品质因素的主次顺序为柠檬酸添加量、紫薯汁与香芋汁的配比、白砂糖添加量、复配胶添加量,并且紫薯香芋果冻的最优配方为紫薯汁与香芋汁的配比1∶1,白砂糖9%,柠檬酸0.2%,复配胶1.5%。经此配方制出的果冻色泽均匀一致、口感爽滑、酸甜可口、细腻柔软,感官评分为86.6分,pH值为4.04,可溶性固形物含量为15.28%。

紫薯粉对米粉食用品质和理化特性的影响

该研究制备了不同紫薯粉添加量对米粉食用品质和理化特性的影响。结果表明,相较于0%添加量(以早籼米质量计,下同),5%~25%添加量(质量分数,下同)紫薯米粉的花色苷、总酚含量分别增加了61.79%~223.58%、38.64%~89.77%,血糖生成指数值降低至61.89。随紫薯粉添加量的增加,紫薯米粉的糊化起始温度(To)、峰值温度(Tp)、终止温度(Tc)逐渐升高,而热焓值(ΔH)逐渐降低。当添加量由0%增加至15%时,米粉的蒸煮损失率、断条率分别由13.49%、24.77%下降至9.65%、18.65%,食用品质逐步提升;当添加量继续增加至25%时,米粉的蒸煮损失率、断条率分别达到12.71%、27.71%,米粉品质下降。综上所述,添加量为15%时,紫薯米粉色泽均匀,色彩艳丽,食用品质及理化特性最佳。

天然紫甘薯色素染制玫瑰永生花工艺的优化

为解决永生花化学染制的污染、不安全的问题,优化天然植物染永生花染色工艺,提升染色效果,以新鲜玫瑰花为试材,天然紫甘薯色素为染料,采用单因子试验及响应面法进行紫甘薯色素染制玫瑰永生花实验,通过测定天然紫甘薯色素的物质成分及染色前后玫瑰永生花的颜色特征值和外观性状观测评估,优化玫瑰永生花的染制工艺。结果显示:紫甘薯色素直染制玫瑰永生花的最佳工艺为pH值5、染料浓度2.0%、染制温度20℃、染制时间6 h;媒染固色最佳工艺为用3%硫酸铜同媒染制3 h。在此条件下,玫瑰永生花上染效率最高,花朵外观形状较好,具有较好的观赏价值。

低糖马齿苋紫薯酱加工工艺优化及其产品品质评价

为了满足消费者对口味多样化、健康饮食的需求,开发一种低糖、零防腐剂的新型复合果酱的科学配方和先进制造方法。以富含人体健康功能因子的马齿苋和紫薯为主要原料,通过单因素实验和正交试验优化了马齿苋紫薯酱的配方,并对最终产品及其贮藏期间的营养物质、理化和卫生指标进行了测定。结果表明,低糖马齿苋紫薯酱的最佳配方为:马齿苋茎叶汁紫薯块根浆质量比为5:5,柠檬酸添加量为0.3%,山梨糖醇添加量为25%,增稠剂添加量为0.4%。按此配方制得的马齿苋紫薯酱色泽呈紫红色,酱体均匀,口感细腻,酸甜适中,具有马齿苋和紫薯特有的香味,感官评分为90.5±0.4分。最终产品的可溶性固形物为42.32%±1.43%,总糖为13.41±0.52 g/100 g,pH3.61±0.18,粗蛋白为0.83±0.08 g/100 g,VC为3.77±0.11 mg/100 g,黄酮为4.18±0.10 mg/g,多酚为2.05±0.13 mg/g,花青素为37.27±0.84 mg/100 g,以上理化指标及卫生指标均达到果酱类的国家标准。马齿苋紫薯酱对DPPH自由基的IC50值为7.071 mg/mL,表明该酱具有一定的抗氧化活性。马齿苋紫薯酱分别在25℃和37℃条件下贮藏1个月后,感官评分及各营养成分均有一定程度下降,菌落总数有所增加,但仍符合果酱国家标准。本项研究结果可为马齿苋和紫薯的精深加工及马齿苋紫薯酱的标准化生产提供参考依据。

药山国家级自然保护区外来入侵物种调查及对策研究

云南药山国家级自然保护区拥有15598.32 hm^(2)森林资源,其林分物种丰富,分布有163科809属2366种种子植物。丰富的气候类型及人为活动的存在,为外来物种入侵提供有利条件。通过对药山国家级自然保护区外来入侵物种种类、发生地点、发生范围、发生面积、发生规律、危害程度和传播途径等因子开展调查,分析外来物种入侵对药山国家级自然保护区的风险,并结合实际提出相应的防控对策措施。

紫薯桂花富硒面包的研制

以紫薯粉、桂花粉、富硒酵母等为主要原料,通过研究原料配比以及工艺参数制作紫薯桂花富硒面包。以紫薯粉添加量、桂花粉添加量、富硒酵母添加量为单因素,考察各因素对紫薯桂花富硒面包的影响,在单因素实验的基础上,结合响应面分析实验,得出紫薯桂花富硒面包制作的最佳优化条件。紫薯桂花富硒面包的最佳配方为:以小麦粉100 g计,紫薯粉添加量为10.33 g,桂花粉添加量为6.21 g,富硒酵母添加量为1.63 g。其他辅料固定用量为:黄油18 g,盐1 g,水40 g,鸡蛋15 g,糖20 g。在此配方下制作出来的面包具有紫薯风味和桂花香气,香甜可口,同时各项理化与卫生指标检测结果表明制作出的紫薯桂花富硒面包符合国家标准。

紫甘薯新品种福宁紫4号的选育

为选育高产优质紫甘薯新品种,以福薯13号为母本,采用集团杂交育成的甘薯新品种福宁紫4号,于2012—2013年参加福建省区域试验.结果表明,福宁紫4号2a平均鲜薯亩产量2888.72kg,比对照品种金山57(CK1)增产7.38%;薯干亩产量672.78kg,比CK1增产1.84%;并于2015年通过福建省品种审定,2019年通过农业农村部品种登记.福宁紫4号具有高产、抗病、较优质、适应性广等特点,早、晚薯均可种植,适宜在福建省大面积推广应用.

紫薯核桃双层饼干工艺研究

以紫薯、核桃为主要原料研制紫薯核桃双层饼干,通过单因素试验确定紫薯泥用量、核桃碎用量和烘烤温度对饼干品质的影响,再通过正交试验确定紫薯核桃双层饼干的最佳配方和工艺。结果表明,影响紫薯核桃双层饼干感官品质各因素主次顺序为烘烤温度>紫薯泥用量>核桃碎用量,紫薯核桃双层饼干的最佳配方和工艺中各组分用量为低筋面粉100 g,紫薯泥20 g,核桃碎15 g,植物油30 g,小苏打0.5 g,鸡蛋5 g,牛奶10 g,绵白糖30 g,上火温度170℃,下火温度150℃。由此配方和工艺制得的紫薯核桃双层饼干颜色鲜亮,色泽均匀,核桃碎层呈现金黄色,紫薯泥层呈现紫罗兰色,并有紫薯和核桃的特殊风味,口感细腻、甜味适中。

不同熟化方式对速冻熟紫薯品质的影响

为深入研究冻前不同熟化方式对速冻熟紫薯品质的影响,本实验以‘紫罗兰’紫薯为原料,采用蒸制、微波制和烤制3种熟化方式处理速冻熟紫薯,并对挥发性成分、色泽、微观结构、花色苷含量和抗氧化活性等进行分析。结果表明,不同熟化方式能够引起速冻熟紫薯中挥发性风味物质的重新分布,提供更多的芳香气味和独特的风味。熟化处理使速冻熟紫薯内组织结构发生变化,使其更易于消化,同时不同熟化处理紫薯花色苷含量也有显著差异,其中蒸制熟紫薯达4.12 mg/g,与鲜紫薯(3.36 mg/g)相比显著提高(P<0.05)。经液相色谱串联质谱(liquid chromatography tandem mass spectrometry,LC-MS/MS)分析鉴定出的紫薯花色苷共有六大类,主要是芍药色素和矢车菊素,蒸制熟紫薯中芍药花素占比最大,达到总量的84.12%,较好地保留了紫薯营养成分和色泽。此外,熟化处理还提高了速冻熟紫薯中花色苷在胃肠消化过程中的释放量,进而显著提高了其抗氧化活性(1,1-二苯基-2-三硝基苯肼自由基清除率、2,2-联氮基双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除率和O_(2)^(-)·清除率),抑制了消化酶(α-淀粉酶和α-葡萄糖苷酶)活性,同时改变了紫薯花色苷酰化速率,提高其稳定性。综合分析得出,蒸制熟化可以更好地稳定速冻熟紫薯中的花色苷,使其具有良好的贮藏稳定性。本研究可为方便紫薯食品的开发提供一定的理论参考。

不同干燥工艺下紫薯全粉品质分析

为筛选出适合工业化生产的高花色苷含量低糊化度的紫薯生全粉制备工艺,对单一型热风干燥、微波干燥及复合型热风联合微波干燥等技术下制作紫薯全粉的花色苷、糊化度、感官评分、综合评分等指标数值变化进行测定和分析。结果表明:最优单一热风干燥条件为40℃干燥8 h,此时紫薯全粉花色苷含量1.648 mg/g,糊化度23.39%,综合得分为97.01分,生产出的紫薯生全粉品质好但耗时久;最优单一微波干燥条件为420 W干燥10 min,此时紫薯全粉花色苷含量2.645 mg/g,糊化度高达93.33%,此时综合得分为82.00分,微波干燥法制得的紫薯全粉普遍糊化度过高,不适宜用作紫薯生全粉生产;最优热风联合微波干燥条件为热风温度50℃干燥水分含量40%时转换280 W微波干燥至水分含量8%以下,花色苷含量为1.161 mg/g,糊化度为59.11%,该法制得紫薯全粉综合评分为84.04分。热风联合微波干燥操作控制简易,能在大幅缩短干燥时间的前提下保证紫薯生全粉的品质,适用于工业化快速生产。

复合乳酸菌发酵紫薯汁工艺优化

乳酸菌可增强紫薯花青素生物转化率.以花青素含量为指标,对筛选的L.plantarum zrx03、L.rhamnosus zrx01、L.acidophilus zrx02、P.pentosaceus Mi515四株乳酸菌进行复配,优选出最佳复配比例.在此基础上运用单因素和响应面试验,探究四株复配乳酸菌发酵紫薯汁时的发酵时间、接种量、糖含量等参数对紫薯汁的感官及产品中活菌数的影响.结果表明:当菌种复配比例为L.plantarum zrx03∶L.rhamnosus zrx01∶L.acidophilus zrx02∶P.pentosaceus Mi515=4∶3∶2∶2时,发酵紫薯汁中花青素含量最高;单因素试验和响应面试验表明,当发酵时间为12 h、接种量为3%、含糖量为5%时发酵紫薯汁的感官评分和活菌数均达到最大值,分别为(96.07±0.28)分和(10.98±0.32)lg CFU/mL,且最佳发酵条件下,发酵紫薯汁中含花青素量可达7.41 mg/100 mL,与未发酵紫薯汁中含花青素量相比显著提高了65.03%.

基于模糊数学综合评价法的改性紫薯饼干的制备工艺优化

本研究以紫薯为原料,对其采用微波联合高压处理以达到提高其抗氧化能力及抑制其褐变反应的目的,然后将改性后的紫薯进一步用于制作饼干,并利用正交试验与模糊数学综合评价法优化紫薯饼干的制作配方。以花青素含量和多酚氧化酶活性为指标,通过单因素实验得到微波联合高压处理紫薯的最优参数为微波功率450 W、微波时间20 min、高压温度115℃、高压时间40 min,在此优化条件下的改性紫薯的花青素含量和多酚氧化酶活性分别比原料升高了2.56倍和降低了45.71%。然后以感官评价为指标,通过正交试验和模糊数学综合评价法优化出紫薯饼干的最佳制作配方为低筋面粉40 g、紫薯粉60 g、白砂糖45 g、黄油75 g、鸡蛋60 g、食盐1 g,所制作的紫薯饼干色泽均匀、外形完整、口感松脆且具有紫薯的香气。

紫甘薯源花青素的抗氧化活性及模拟消化稳定性研究

试验旨在研究紫甘薯源花青素的抗氧化活性及模拟胃肠道消化对其活性的影响。通过微量法和比色法测定紫甘薯源总花青素含量,并测定其体外抗氧化活性,然后进行胃肠道模拟消化试验,测定紫甘薯源花青素消化后的总花青素含量及抗氧化活性。结果表明:紫甘薯源花青素具有较强的2,2’-联氮-二(3-乙基-苯并噻唑-6-磺酸)二胺盐[2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS]自由基清除能力、羟自由基(·OH)清除能力和铁离子总抗氧化能力(ferric ion reducing antioxidant powor,FRAP),均显著强于维生素C(VC),且与浓度成正比,半抑制浓度(half maximal inhibitory concentration,IC50)值分别为0.16、2.47、0.11 mg/mL。并且对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基也具有一定的清除能力,IC50值为0.73 mg/mL。在模拟胃肠液消化后0.5~2.0 h,紫甘薯源花青素的总花青素含量显著高于模拟消化前(P<0.05),并且对·OH的清除能力极显著高于模拟消化前(P<0.01);在模拟胃肠液消化的3.0~4.0 h,紫甘薯源花青素的总花青素含量低于模拟消化前,而对·OH的清除能力和FRAP的抗氧化活性极显著(P<0.01)低于模拟消化前。综合来看,紫甘薯源花青素的抗氧化活性与浓度成正比,且优于VC。模拟胃肠液消化0~2.0 h,紫甘薯源花青素具有一定稳定性,总花青素含量和抗氧化活性提高,而在3.0~4.0 h紫甘薯源花青素稳定性明显减弱,总花青素含量和抗氧化活性显著降低。

不同生物酶协同植物乳杆菌发酵对 紫甘薯生全粉理化特性的影响

以紫甘薯生全粉为原料,使用植物乳杆菌(Lactobacillus plantarum)、植物乳杆菌+纤维素酶(Cellulase)+普鲁兰酶(Pullulanase)、米根霉(Rhizopus oryzae)、植物乳杆菌+纤维素酶+普鲁兰酶+米根霉4种方式发酵,研究紫甘薯生全粉在不同发酵方式和时间下基本成分、理化特性、色泽和热力学特性的变化情况。结果表明:发酵使紫甘薯生全粉蛋白质、灰分、脂肪、SDF、DPPH自由基清除能力、持油性升高,淀粉、IDF、总酚、花青素、持水性、吸水膨胀性降低;热力学实验表明发酵使紫甘薯生全粉的ΔH升高,T_(0)提前,T_(c)推迟,具有良好的热特性;4种发酵产酸能力由强到弱依次为Lac/Cel-Pul>Lac>Lac/Cel-Pul/Rhi>Rhi,颜色变化与其一致。生物酶处理对紫薯生全粉的理化性质具有显著性影响,能够有效改善紫薯生全粉的加工特性。