果胶酶及浸渍处理对苹果酒多酚组分的影响

为了探究果胶酶及浸渍处理对苹果酒多酚组分和品质的影响,用4种不同方式(清汁发酵不加酶、清汁发酵加酶、浸渍发酵不加酶、浸渍发酵加酶)酿造苹果酒,并测定其在发酵过程中的多酚组成、理化指标和抗氧化指标。结果表明,果胶酶和浸渍处理分别能够增加和降低苹果酒酸度,对酒精度没有显著影响。果胶酶和浸渍处理能够显著提高苹果酒中总酚的含量。共检测出9种多酚组分,包括酚酸类的没食子酸、绿原酸、咖啡酸、对香豆酸、阿魏酸和黄酮类的儿茶素、金丝桃苷、根皮苷和根皮素。果胶酶添加能促进绿原酸和根皮苷降解生成咖啡酸和根皮素,浸渍处理能促进果渣中酚类物质浸出,从而提高酒样中多酚组分含量,提高酒体抗氧化活性。果胶酶和浸渍处理对苹果酒品质有显著提高。     

反相高效液相色谱法测定猕猴桃酒中的多酚物质

建立了猕猴桃酒中多酚的RP-HPLC检测方法该方法的最低检测限小于1．0mg／L,加标回收率均大于90％。RSD％小于6％,说明该方法准确可靠。用该方法对自制猕猴桃酒中多酚物质进行检测,得出样品中主要有：原儿茶酸、儿茶素、香草酸、咖啡酸、表儿茶素、香豆酸、槲皮素等13种多酚物质。     

苹果品种和酿造工艺对苹果酒中酚类物质的影响研究

研究不同苹果品种及加工工艺与苹果酒中最终酚类物质的含量和种类的关系,了解不同苹果酒中酚类物质含量的差异.选用甘肃天水提供的两种不同工艺的6款苹果酒样,测定其中的总酚、酚酸及黄烷-3-醇的含量.苹果酒的总酚含量(以没食子酸计)较高,3种苹果酒中的主要酚类物质中,酚酸主要以原儿茶酸、绿原酸、p-香豆酸以及咖啡酸为主;黄烷-3-醇以儿茶素和表几茶素居多.结果表明,不同苹果品种之间酚类物质的含量及类别差异很大,相同品种的苹果酒中多酚的构成及含量会受到酿造工艺的影响.     

不同原料苹果酒的酿造特性研究

以‘金世纪’单一苹果品种及‘金世纪’、‘嘎啦’、‘澳洲青苹’混合（1∶1∶1）苹果品种为原料酿造苹果酒,并对其进行理化指标、多酚物质、香气成分测定及感官品评。结果表明,两种苹果酒理化指标差异不显著（P＞0.05）;混合发酵苹果酒中的酚类物质总量（61.88 mg/L）显著高于单独发酵苹果酒（56.90 mg/L）（P＜0.05）,其中以原儿茶酸、儿茶素、原花青素、表儿茶素和绿原酸为主。香气主要以醇类和酯类物质为主,两种苹果酒中醇类物质含量分别为216.83 mg/L和78.85 mg/L;酯类以乙酸乙酯、乙酸丙酯、乳酸乙酯和乙酸己酯为主,前三者在混合发酵苹果酒中含量均显著高于单独发酵苹果酒（P＜0.05）,使其香气更加浓郁和复杂。混合发酵苹果酒在澄清度、回味、香气、风味平衡方面更好,但在色泽方面稍差。因此,混合苹果品种发酵更适合于苹果酒的酿造。     

热带假丝酵母对苹果酒风味物质合成的影响

为探究热带假丝酵母(Candida tropicalis)对苹果酒风味物质合成的影响。试验将分离自苹果的1株Candida tropicalis用于苹果酒发酵试验,改变酿酒酵母和Candida tropicalis混菌发酵接种比例,测定苹果酒相关理化指标和挥发性风味物质。结果表明:酿酒酵母和Candida tropicalis不同接种比例下苹果酒中共鉴定出38种挥发性风味物质,包括7种酸、15种醇、7种酯、8种羰基化合物和2种萜烯类化合物。通过热图聚类,酿酒酵母纯种发酵及接种Candida tropicalis的混菌发酵的挥发性风味物质明显区分;酿酒酵母纯种发酵下,以乙酯类化合物的合成为主;而Candida tropicalis添加则主要影响乙酸乙酯、乙酸异戊酯、高级醇和呋喃类化合物的合成。基于共现性网络分析表明,Candida tropicalis的加入对苹果酒风味物质相互作用影响较大,提高了苹果酒风味物质的复杂性。试验结果为Candida tropicalis在苹果酒酿造中的应用提供理论数据。     

高效液相色谱法快速测定红富士苹果渣中的6种多酚

为了建立快速检测苹果多酚的反相高效液相色谱法,通过选择合适的流动相,采用梯度洗脱并且调整进样量及流速,最终达到了很好的分离效果。该方法能在20min内检测出苹果渣中的6种酸性酚和黄酮类物质,检测限为0.008～0.088μg/g,样品加标回收率均>90%,相对标准偏差为1.3%～2.4%,说明该方法准确可靠。用该方法检测了红富士苹果渣中多酚的含量,实验表明,样品中的多酚类物质包括绿原酸、儿茶素、表儿茶素、芦丁、根皮苷等。     

用HPLC测定苹果酒中的酚类物质

确立了用HPLC测定苹果酒中酚类物质的方法，各酚的回收率均在85％之上，说明该方法准确可靠。     

“减硫法”酿造对苹果酒中挥发性香气成分的影响

采用顶空固相微萃取-气相色谱-质谱联用法（HS-SPME-GC-MS）对“减硫法”和常规法酿造的小国光苹果酒中的挥发性香气 物质进行测定和分析。 结果表明,两种苹果酒中共检测到挥发性香气物质66种,包括15种醇类、30种酯类、7种脂肪酸类、3种酮类、6种 芳香族类、3种萜烯类和2种其他类。与常规法酿造相比,“减硫法”酿造有助于提升苹果酒中酯类物质,特别是具有丰富果香和花香的 乙基酯类物质的含量,增加了36.11 mg/L;同时还能有效降低苹果酒中的高级醇,特别是具有酒精味和溶剂味的异戊醇的含量,降低 了14.68 mg/L;但也会降低苹果酒中脂肪族类、芳香族类和萜烯类物质的含量（分别为9.98 mg/L,10.77 mg/L,1.54 mg/L）,造成苹果酒 中乳酪香、烘烤香和部分花香的减弱。 适当减少二氧化硫的使用量可在一定程度上改善苹果酒的香气品质。     

酵母菌种对苹果酒主发酵过程中的多酚组成及抗氧化活性的影响

通过研究国内外常用的4种酿酒酵母在苹果酒发酵过程中对多酚组成和抗氧化活性的影响,结果表明,在苹果酒发酵过程中,不同酵母对苹果发酵液中多酚总抗氧化能力的变化影响不大,但对鲜酒中多酚组成却有不同的影响。酵母菌1#（WLP775）、2#（#4766cider）发酵的苹果酒F1#、F2#在多酚组成上差异较大,抗氧化能力上差异亦较大;酵母3#（EXCE．SP）、4#（HARM-N°5）发酵的苹果酒F3#、F4#在多酚组成上差异较小,抗氧化能力上差异亦较小。     

基于电子鼻和气相色谱-质谱联用技术分析不同品种苹果酒香气物质

以陕西白水的嘎啦、红星、瑞雪、瑞阳4种苹果为原料酿造苹果酒,采用电子鼻（E-nose）和顶空固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）技术分析4种苹果酒香气物质。结果表明,电子鼻检测到4种苹果酒的香气特性差异较大,利用主成分分析（PCA）法和线性判别分析（LDA）法可完全将其区分开;HS-SPME-GC-MS共检测出76种挥发性香气物质,包括醇类11种、酯类43种、醛类7种、酮类3种、酸类7种、萜烯和其他5种;嘎啦、红星、瑞雪、瑞阳苹果酒分别有66种、43种、45种、47种香气物质,总含量分别为7.17 mg/L、7.08 mg/L、6.64 mg/L、7.56 mg/L,且4种酒共有特征香气物质包括：丁酸乙酯、2-甲基丁酸乙酯、乙酸异戊酯、己酸乙酯、辛酸乙酯、癸酸乙酯。电子鼻结合HS-SPME-GC-MS分析可以成功区分不同品种苹果酿造苹果酒的挥发性成分。     

Colonic availability of polyphenols and D-(-)-quinic acid after apple smoothie consumption

Scope : The aim of this study was to determine the amounts of polyphenols and D ‐(?)‐quinic acid reaching the ileostomy bags of probands (and thus the colon in healthy humans) after ingestion of apple smoothie, a beverage containing 60% cloudy apple juice and 40% apple puree. Methods and results : Ten healthy ileostomy subjects each ingested 0.7 L of apple smoothie (a bottle). Their ileostomy bags were collected directly before and 1, 2, 4, 6 and 8 h after smoothie consumption, and the polyphenol and D ‐(?)‐quinic acid contents of the ileostomy fluids were examined using HPLC‐DAD and HPLC‐MS/MS. The total polyphenol and D ‐(?)‐quinic acid content of the apple smoothie was determined to be 1955.6±124.6 mg/0.7 L, which is very high compared to cloudy apple juices. The most abundant substances found in the ileostomy bags were oligomeric procyanidins (705.6±197.9 mg), D ‐(?)‐quinic acid (363.4±235.5 mg) and 5‐caffeoylquinic acid (76.7±26.8 mg). Overall recovery of ingested polyphenols and D ‐(?)‐quinic acid in the ileostomy bags was 63.3±16.1%. Conclusions: The amounts of polyphenol and D ‐(?)‐quinic acids reaching the ileostomy bags are considerably higher after apple smoothie consumption than after the consumption of cloudy apple juice or cider. These results suggest that the food matrix might affect the colonic availability of polyphenols, and apple smoothies could be more effective in the prevention of chronic colon diseases than both cloudy apple juice and apple cider.     

苹果酒发酵过程中绿原酸胁迫对酿酒酵母生理特性的影响

在苹果酒发酵过程中,酿酒酵母会对各种胁迫和环境变化做出代谢应答.绿原酸是苹果和苹果酒中含量相对较高的一种苹果多酚类物质.本文以绿原酸为代表性苹果多酚,考察不同质量浓度的绿原酸胁迫对酿酒酵母生理特性的影响.结果表明:酿酒酵母CICC 31084在绿原酸胁迫下,主要通过改变胞内超氧化物歧化酶(SOD)活性、过氧化氢酶(CA...     

Modified immunoliposome sandwich assay for the detection of Escherichia coli O157:H7 in apple cider

Detection of Escherichia coli O157:H7 in fruit juices such as apple cider is necessary for diagnosis of infection and epidemiological investigations. However, inhibitors in the apple cider, such as endogenous polyphenols and acids, often decrease the sensitivity of PCR assays and immunoassays, thus routinely requiring laborious cell separation steps to increase the sensitivity. In the current study, polyethylene glycol (PEG)-derivatized liposomes encapsulating sulforhodamine B were tagged with anti-E. coli O157:H7 antibodies and used in an immunoliposome sandwich assay for the detection of E. coli O157:H7 in apple cider. Even without prior separation, this assay can detect E. coli O157:H7 in apple cider samples inoculated with as few as 1 CFU/ml after an 8-h enrichment period. The lower limit of detection in pure cultures without enrichment was 7 x 10(3) CFU/ml (280 CFU/40-microl sample). PEGylated immunoliposomes are suitable as an analytical reagent for the detection of E. coli O157:H7 in fruit juices containing polyphenols.     

沸石负载壳聚糖对高酸苹果发酵酒澄清工艺

以鲁加6 号苹果发酵酒为原料,根据Box-Behnkend 的中心组合试验设计原理,在单因素的基础上采用响应面分析法,建立沸石负载壳聚糖澄清苹果酒的二次多项数学模型,并以苹果酒澄清度为响应值和等高线建立响应面,研究沸石负载壳聚糖添加量、处理时间、处理温度对苹果酒澄清效果的影响。结果表明：沸石负载壳聚糖澄清苹果酒的最佳工艺条件为沸石- 壳聚糖澄清剂添加剂量11.6g/L、处理时间47.6min、处理温度27℃;与常规法澄清苹果酒相比,经过处理的苹果酒澄清度提高了16.8%,可溶性蛋白含量、总酚含量均有显著降低,而总酸、可溶性固形物含量、儿茶素、绿原酸、咖啡酸含量变化不明显,表儿茶素含量降低。     

Polyphenol profiles of apple juices

Focusing on 17 constituents, the polyphenol profiles of juices freshly made from various dessert (n = 4) and cider apple cultivars (n = 7) as well as commercially available apple juices (n = 24) were investigated using high-performance liquid chromatography-photodiode array detection (HPLC-DAD) and (HPLC)-electrospray ionization-tandem mass spectrometry (ESI(neg)-MS/MS) analyses. Significant differences in the total polyphenol content as well as the profiles of the apple cultivars under study were observed. For dessert apples the total polyphenol content ranged from 154 to 178 mg/L, whereas for 'old' German cider apple cultivars 261-970 mg/L were determined. Boskoop showed the highest (970 mg/L) and Granny Smith the lowest (154 mg/L) polyphenol content of the freshly prepared samples under study. Hydroxycinnamic acids, with chlorogenic acid as dominating constituent, ranged from 57 to 68 mg/L as well as from 134-593 mg/L in juices made from dessert apples and that from cider apples, respectively. Dessert apple juices showed lower contents of dihydrochalcones (10-35 mg/L) and flavan-3-ols (50-95 mg/L) compared to that of cider apples (34-171 mg/L and 70-393 mg/L, respectively). Quercetin and its derivatives were found from 0.4-4 mg/L and 0.4-27 mg/L in juices made from dessert apples and that of cider apples, respectively. Compared with freshly made juices, lower contents of polyphenols were determined in the commercial samples under study. Amounts ranging from 110-459 mg/L, dominated by chlorogenic acid with concentrations from 53-217 mg/L, were determined. Information about cultivar-typical apple polyphenol content and profile is important for bioactivity studies and, consequently, essential for the development of consumer-relevant products with particular nutritional functionalities.     

Apple quality,storage, and washing treatments affect patulin levels in apple cider

Patulin is a mycotoxin produced primarily by Penicillium expansum, a mold responsible for rot in apples and other fruits. The growth of this fungus and the production of patulin are common in fruit that has been damaged. However, patulin can be detected in visibly sound fruit. The purpose of this project was to determine how apple quality, storage, and washing treatments affect patulin levels in apple cider. Patulin was not detected in cider pressed from fresh tree-picked apples (seven cultivars) but was found at levels of 40.2 to 374 microg/liter in cider pressed from four cultivars of fresh ground-harvested (dropped) apples. Patulin was not detected in cider pressed from culled tree-picked apples stored for 4 to 6 weeks at 0 to 2 degrees C but was found at levels of 0.97 to 64.0 microg/liter in cider pressed from unculled fruit stored under the same conditions. Cider from controlled-atmosphere-stored apples that were culled before pressing contained 0 to 15.1 microg of patulin per liter, while cider made from unculled fruit contained 59.9 to 120.5 microg of patulin per liter. The washing of ground-harvested apples before pressing reduced patulin levels in cider by 10 to 100%, depending on the initial patulin levels and the type of wash solution used. These results indicate that patulin is a good indicator of the quality of the apples used to manufacture cider. The avoidance of ground-harvested apples and the careful culling of apples before pressing are good methods for reducing patulin levels in cider.     

茶多酚苹果酒的发酵新工艺中试研究

以浓缩苹果汁为原料,采用固定化酵母发酵技术,加入茶多酚作为抗氧化剂,进行苹果酒中试发酵试验,通过测定发酵过程中的酒精度、酸度、透光率、残糖等理化指标的变化情况,考察中试后发酵速度和发酵效果的变化。结果表明:当发酵体积扩大50倍后,苹果酒发酵效果与小试样小体积状态下的发酵效果无显著差异,总的变化趋势趋于一致。