柑桔汁微生物脱苦的研究

以ＡＳ１．１４菌种,采用Ｋ－角叉胶进行包埋,研究固定化醋酸杆菌在柑桔汁苦味脱除中的应用。重点研究了选择性培养条件的确定、固定化细胞生物反应器的设计及应用。表明：ＡＳ１．４１在柑桔法中脱苦中可行的。另外,把ＡＳ１．４１菌种用于柑桔汁脱苦的国内外尚属首次。     

固定化醋酸杆菌细胞特性的研究

研究了用于柑桔汁脱苦的固定化醋酸杆菌细胞的特性,研究表明：固定化细胞脱苦最佳供氧为：摇床转速160r/min,最适pH为4.5,最适温度为25℃;而细胞脱苦的相应条件分别为160r/min,pH5.5,25℃。低浓度NaCl对固定化细胞和游离细胞的脱苦都有强烈的抑制作用;固定化细胞在柠碱浓度达到30mg/kg后,柠碱降解速度趋于饱和,而游离细胞的柠碱浓度则为35mg/kg;固定化细胞的热稳定性比游离细胞好。     

柑桔类果汁中柠碱的脱苦方法

就柑桔中苦味物质的分布及其主要成分进行了论述，并介绍了几种柑桔类果汁中柠碱的脱苦方法。     

柑桔制品中的苦味物质—柠碱

<正> 类柠檬素(Limonoids)是一组三萜系衍生物,包括有二十九种成员物质,其中四种具有强烈的苦味,即柠碱(Limonin)、Ichangin、诺米林(Nomilin)及诺米林酸(Nomilinic acid)。而柠碱是柑桔制品中重要的苦味源,它是一种三萜系二内酯化合物,分子结构中含有一个呋喃环,一组酮型结构,一组环氧结构及二个内酯环。目前仅     

柑桔类果汁苦味物质的脱除研究

柠碱和柚苷是柑桔汁和柑桔其他制品中的主要苦味成分,采用吸附脱苦法、酶脱苦法、β-环糊精脱苦法、乙烯利代谢脱苦法及其他脱苦法可将它们除去,文中还提出了采用综合脱苦法应用于生产实际的观点。     

柑桔类果汁苦味物质的脱除研究

柠碱和柚苷是柑桔汁和柑桔其他制品中的主要苦味成分,采用吸附脱苦法、酶脱苦法、β-环糊精脱苦法、乙烯利代谢脱苦法及其他脱苦法可将它们除去,文中还提出了采用综合脱苦法应用于生产实际的观点。      

柑桔果实主要苦味成分的分布及橙汁脱苦技术研究

柑桔果实中主要苦味成分是柚苷和柠碱，本文对它们在主栽柑桔品种果实中的分布情况和利用吸附树脂脱除橙汁苦味的技术进行了研究，并筛选出了优良的国产树脂。     

三种脱苦方法脱除柑桔汁苦味的研究

柠碱和柚苷是柑桔汁及柑桔其它制品中主要苦味成份。本文着重研究了酶法脱苦、β—环糊糟脱苦和乙烯利代谢脱苦三种方法脱除柑桔汁内苦味的效果和工艺实施。进行了黑曲霉(Aspergillus niger.)不同菌株产酶筛选试验,对由黑曲霉诱导产生的柚苷酶及其固定化柚苷酶的一些基本酶学特性进行了探索性研究,对β—环糊精脱苦的机制、工艺及效果也进行了研究,并提出了采用综合脱苦的方法应用于生产实际的措施。     

柑桔发酵酒脱苦技术研究

柑枯发酵酒中苦味物质主要由柠檬苦素,柚皮苷等组成,本研究采用吸附法,酶制剂等脱苦方法,确定最佳酶制剂脱苦工艺参数。     

柑橘果汁中的类柠檬苦素及其脱苦方法

介绍了柑橘果汁中的类柠檬苦素苦味，类柠檬苦素苦味物质的结构，由类柠檬苦素引起的后苦味的形成机理．以及目前研究的类柠檬苦素苦味物质的脱除方法。     

Important flavonoids and limonin in selected Thai citrus residues

The distributions of important flavonoids and limonin in selected Thai citrus residues were investigated in this study. The residues of interest were peels of pomelo (Citrus grandis (L.) Osbeck cv. Kao Yai and cv. Kao Nampheung), residues after juice extraction of tangerine (Citrus reticulata Blanco cv. Sainamphueng and cv. Bangmod) and peels and residues after juice extraction of kaffir lime (Citrus hystrix DC). Flavonoids were characterized and quantified in terms of flavanones, i.e., naringin and hesperidin, and polymethoxyflavones (PMFs), i.e., nobiletin, sinensetin and tangeretin. Naringin was a dominant flavanone in polmelo peels. Three PMFs were found in all samples with varying contents. Comparing the samples, residues from tangerine cv. Bangmod exhibited the highest value of each PMFs. Limonin was present in small amounts in pomelo peels and residues after juice extraction of tangerine and kaffir lime. All samples were good sources of dietary fibre, with a total dietary fibre content of more than 60 g/100 g on a dry weight basis with high proportion of soluble dietary fibre.     

冷冻对柑橘汁过滤性能的影响

过滤是果汁生产中固液分离的重要手段。冷冻至 - 2 2℃的柑橘汁的粘度从原来的 16 .5 m· Pa/s降低至 2 .80 m·Pa/s,室温下自然解冻后出现固液分离现象 ,经离心分离后 ,平均过滤速度是未冷冻过的柑橘汁过滤速度的 3倍 ,但冷冻温度对可溶性固形物含量基本没有影响     

Development and validation of a decigram-scale method for the separation of limonin from limonin glucoside by C-18 flash chromatography

A preparative method for decigram-scale polishing of limonin glucoside (1) with regard to removing traces of limonin (2), the main bitter principle in Citrus, is reported. During the method development and up-scaling stages, sample purity, sample size, solvent amounts, and drying conditions were varied. The resulting polishing method consists of a simple step gradient that utilises food grade solvents, ethanol and water at 15% EtOH and 50% EtOH steps. Using a 75 × 300 mm C-18 column, this method is capable of processing 20 g of material per run in less than 3 h. Recovery of the purified limonin glucoside following evaporation of the solvent was 93.5% (±2.8, n = 6) and the limonin concentrations in the resulting materials were found to be reduced 10- to 15-fold.     

Effect of pH,temperature and maturity on pectinmethylesterase inactivation of citrus juices treated by high-pressure homogenization

The effects of high-pressure homogenization (HPH) at 150 MPa combined with heating at 58, 63 and 68 °C on inactivation of pectinmethylesterase (PME) were studied in orange and Clementine juices. Juices covering a range of total soluble solids (°Bx) to acid ratios (10.2–15.0 in oranges and 9.2–19.4 in Clementines) were adjusted to pH 3.1, 3.5 and 3.9 before homogenization. Results indicated how the residual PME activity of homogenized samples was greatly attenuated by lowering the pH and in a lesser extent by increasing the homogenization temperature (finding orange enzymes more HPH sensitive than their Clementine counterparts). Generally, ripeness of fruits had little influence on PME inactivation (especially in Clementine juices). In any case, orange and Clementine samples with pH 3.1 and homogenized at 68 °C showed residual PME activities below 10% of the initial value from their respective fresh juices.     

Sorption of citrus flavour compounds on XAD‐7HP resin during the debittering of grapefruit juice

Grapefruit juice made from concentrate was debittered using a laboratory‐scale downflow column packed with XAD‐7HP adsorbent resin. Sorption of the bitter principle naringin was analysed by high‐performance liquid chromatography. In addition, the influence of the debittering process on the flavour of the juice was investigated using headspace gas chromatography for the volatile flavour compounds α‐pinene, β‐myrcene, d‐limonene, α‐terpineol and β‐caryophyllene. Kinetic constants were determined for all substances using the Lagergren adsorption model. The debittered juices showed a selective shift in their reduced flavour profile. Reduction of naringin to 51.28% of its initial value led to a decrease in α‐terpineol to 43.05%, whereas the other flavour compounds ranged from 76.27% (β‐myrcene) to 92.76% (β‐caryophyllene). The column flow rate influenced the adsorption of α‐terpineol and naringin. The highest affinity for adsorption was consistently observed for the off‐flavour α‐terpineol, which indicates a promising option for its selective removal from processed juices during debittering.