α-葡聚糖酶在蔗汁澄清工艺中的应用研究

使用细丽毛壳菌发酵生产的α-葡聚糖酶粗酶液在蔗汁中进行试验,试验结果表明,在混合汁中添加粗酶液,用常规的亚硫酸法工艺进行澄清处理,过滤速度与沉降速度均提高了40%,葡聚糖除去率为20%,清汁混浊度降低60%,色值降低10%。在混合汁、清汁与糖浆中添加粗酶液,葡聚糖含量分别减少20%、15%与5%。葡聚糖酶的加入对蔗糖无影响。     

Investigation of TiO2 nanoparticle efficiency on decolourisation of industrial date syrup

The TiO₂ nanoparticle photocatalyst was used to decolourise industrial date syrup. The effect of TiO₂ concentration (1 and 4% w/v), UV power (15 and 30 w) and processing time (12 and 48 h) on date syrup characteristics was investigated using a factorial design. The colour, turbidity, sugar content, total phenolic compounds, ash content and mineral (K, Na, Ca, Mg and Fe) of date syrup were analysed. The results demonstrated that using TiO₂ nanoparticle as a photocatalyst for the decolourisation of date syrup is an effective and promising method. Colour in all treatments was significantly (P < 0.05) reduced between 30 and 53% in comparison with the initial date syrup (491 000 IU), and the reduction was even higher for date syrup turbidity (between 47 and 75%). The result showed that the process condition significantly affected the colour and turbidity reduction. On the basis of the result, the best treatment was TiO₂ 4%, 15 w and 48 h. Under this condition, date syrup colour, turbidity, ash content, sugar content reduced by 52%, 61%, 13% and 9%, respectively.     

Application of sepiolite in clarification of pomegranate juice: changes on quality characteristics during process

In this study, for the first time, the function of acid‐activated sepiolite clay was evaluated for clarification of pomegranate juice. The optimum conditions of clarification process were achieved using response surface methodology based on juice turbidity as a response. After that, under optimal condition, efficiency of sepiolite, bentonite and combination of these fining agents with gelatin and kieselgel was compared for clarifying pomegranate juice. The results showed that the best conditions for juice clarification were 0.05% (w/v) clay concentration, temperature of 50 °C and time of 2 h. The results revealed that treatments of bentonite–gelatin–kieselgel and sepiolite–gelatin–kieselgel were the most active fining agents that their use led to a reduction of 99.7% in turbidity of pomegranate juice. Kinetic study for different features was performed, and the results indicated that rate of changes in turbidity, viscosity, total phenolic contents and colour with time followed first‐, first‐, zero‐ and zero‐order kinetic models, respectively.     

烟道气饱充上浮技术处理顽性蔗汁工艺

基于烟道气饱充上浮技术处理顽性蔗汁的查定效果,通过单因素和正交试验研究,对浮清汁的澄清工艺进行了优化设计。结果表明,磷酸值对过滤速度、色值的影响最大,对沉降速度、纯度的影响最小;硫熏强度对纯度的影响最大,对过滤速度、色值影响最小;中和pH值对沉降速度、过滤速度有一定程度影响。各因素对还原糖的影响在统计学上不显著(p0.05)。通过评价沉降速度、过滤速度、纯度和色值,分别得到了最优的工艺条件。     

桃红葡萄酒酿造工艺优化研究

研究利用浸渍巨峰葡萄果浆酿制桃红葡萄酒。分析果浆处理和工艺对桃红葡萄酒品质的影响。结果表明,控制果浆色度在2.5~3.0作浸渍过程终点,浸渍结束后分离不超过30%果浆量,调整含糖量为26%并加入酵母进行主发酵。按常规经后发酵、澄清、过滤与检测合格后酿造出桃红色、清亮透明、怡悦和谐的果香与酒香并具有恰当收敛性与酒体完整的桃红葡萄酒。     

Anthocyanin and colour changes during processing of pomegranate (Punica granatum L., cv. Hicaznar) juice from sacs and whole fruit

The effects of clarification and pasteurisation on anthocyanins (ACNs) and the colour of pomegranate juice (PJ) produced from sacs and whole fruits were investigated. Clarification caused a loss of 4% of ACNs in juice from sacs (JFS) and a loss of 19% in juice from whole fruit (JFWF). After pasteurisation, there was an 8–14% and 13–9% loss of ACNs from unclarified and clarified JFS and JFWF samples, respectively. Polymeric colour was very high even in unclarified samples (25–29%). Compared to JFS, higher polymeric colour was formed in JFWF. HPLC analyses of PJ revealed that cyanidin-3,5-diglucoside was the major ACN, followed by cyanidin-3-glucoside and delphinidin-3-glucoside. Cyanidin-3,5-diglucoside showed higher stability to clarification and pasteurisation than cyanidin-3-glucoside in both PJ samples. Cold clarification with only gelatin is recommended for PJ. To prevent excessive ACN loss and the formation of brown colouring, PJ should be subjected to minimal heating.     

混合技术在亚硫酸法澄清工艺的综合应用研究

2006/07年榨季将预灰静态混合器、罐内射流混合系统、扩散孔板混合器和旋流混合器组成的硫熏中和强化反应器系统应用在廖平糖业有限责任公司的澄清工段,使清汁质量和白砂糖产品质量显著提高.可减少硫熏强度1～2 cc,节约石灰约10%.同期清汁重力纯度提高近1%,白砂糖产品色值小于130 IU的占52.47%.     

Clarification of tomato juice by cross‐flow microfiltration

Clarification of fruit and vegetable juice is one of the integrated parts of modern industrial juice processing. This paper describes the clarification of tomato juice through microfiltration process. In this regard, the influence of transmembrane pressure (1, 2 and 3 bar), cross‐flow velocity which corresponds with Reynolds number (300, 1500 and 2500) and temperature (30, 40 and 50 °C) on permeate flux and some properties of clarified juice such as colour, turbidity, density, viscosity, pH and total soluble solid have been studied. The results revealed that the investigated parameters had an increasing effect on the permeate flux and colour and the greatest effect on the permeate flux and colour was supplied by cross‐flow velocity. The other permeate properties did not significantly change with variations of the operating parameters. Eventually, the statistical analysis indicated that the interactional effect of cross‐flow velocity and TMP on the permeate flux was significant.     

Evaluation of CIE-lab colour parameters during the clarification of a sugar syrup from Mesquite pods (Prosopis Pallida L.)

Summary There are several commercial sugar syrups obtained from the Mesquite pods, however their dark-brown colour limits their use in the food industry. In this work we clarified sugar syrups from Mesquite pods by a two-step procedure: (1) lime-milk treatment with the addition of different amounts of calcium hydroxide and aluminium sulphate, and (2) ion-exchange treatment using A-400 anionic and/or C-100 cationic resins. Samples were evaluated for colour using the Hunter Lab colorimeter (Hunter Associates Laboratory Inc, Reston, VA, USA) (L*, a*, b*, ) and for sensory acceptability during the clarification process. The results showed that with the addition of 7.5% calcium hydroxide and 8.0% aluminium sulphate, followed by treatment with the anionic resin A-400, a syrup with a high degree of purity (92.3%) and a lighter-brown colour than other commercial samples could be obtained. The colour values, as measured by the Hunter meter were; a lightness of L* = 6.17 and a yellow colour of 0.74 expressed as a a/b* ratio. A negative correlation was obtained between the total polyphenol content (TP) in the sugar extract and the lightness values (L*); L* = 15.50–0.00511 TP (mg kg^–1). The A-400 resin retained the greatest amount of polyphenols (92.9%). CIE-Lab parameters are proposed as a good means for objective colour comparison with other studies on the clarification of sugar syrups.     

酶法制备不同发酵度高浓大麦糖浆的研究

报道了以饲料大麦为原料、脱脂玉米粉为辅料,酶法生产75%高浓度啤酒酿造用大麦糖浆及其应用于啤酒酿造试验的研究结果。研究表明,以不适用于发芽的大麦与脱脂玉米粉为原料,全酶法可生产出与麦汁成分相近的大麦糖浆,具有丰富的α-氨基氮等酵母营养物质。探讨了生产不同发酵度糖浆的工艺条件。并通过对高浓度糖浆的保质期进行实验,证明75%的浓度可以长期保存的实验结论。采用所研制的糖浆代替30%的麦芽汁进行啤酒酿造试验获得了理想的结果。     

柿子发酵果酒酿造技术和营养成分分析

以柿子为原料,经脱涩、除柄蒂去核、打浆、冷冻、粗滤取汁、果汁脱涩和澄清、过滤、成分调整、控温发酵、压酒、陈酿、澄清、精滤、装瓶杀菌等工序生产得柿子发酵果酒,出酒率可高达65％以上。柿子发酵果酒营养成分分析测定结果表明,柿子果酒中含有极为丰富的维生素和人体所需的生命元素,所含氨基酸达17种之多,氨基酸总含量为53．70mg／100mL,人体必需氨基酸有7种,含量为19．34mg／100mL,占总氨基酸的36．01％。（孙悟）     

蒸发过程糖汁中热敏性物质变化特性的研究

为了更好地制定糖汁澄清工艺条件并为煮糖系统提供高品质的糖浆,本实验研究测定了碳酸法糖厂蒸发过程糖汁中热敏性物质的含量,探索它们的变化规律并分析其致因。结果表明,随着蒸发效数的增加,糖汁pH先升后降,整体下降0.37～0.78;纯度、钙盐、氨基酸态氮及酰胺有所下降;还原糖及色值含量变化呈上升趋势。碳酸法糖厂二碳饱充pH不宜过低,清汁的pH宜控制在中性偏碱。     

基于红糖生产的蔗汁陶瓷膜过滤工艺技术

采用孔径为8、50 nm及500 nm的陶瓷膜对蔗汁进行过滤澄清生产红糖,解决传统红糖制作利用上浮撇泡方式处理蔗汁清净效果差导致成品糖品质低的问题.对比不同孔径陶瓷膜过滤蔗汁渗透通量大小、清净效果及能耗高低,结合红糖生产工艺需求,得出孔径为50 nm的陶瓷膜最适用于蔗汁过滤澄清生产红糖.在适合的操作条件下,考察孔径为5...     

The effects of processing technology on the patulin content of juice during commercial apple juice concentrate production

 The effects of different treatments on the patulin content of apple juice during the production of industrial apple juice concentrate were investigated. Conventional clarification using a rotary vacuum precoat filter was found to be more effective than using ultrafiltration for the removal of patulin from apple juice. The average losses of patulin were 39% and 25% for conventional clarification and filtration, and ultrafiltration, respectively. Washing and handling appeared to be the most critical steps in removing patulin from apples since up to 54% could be removed using high-pressure water spraying. Received: 22 January 1998 / Revised version: 21 April 1998     

The effects of processing technology on the patulin content of juice during commercial apple juice concentrate production

 The effects of different treatments on the patulin content of apple juice during the production of industrial apple juice concentrate were investigated. Conventional clarification using a rotary vacuum precoat filter was found to be more effective than using ultrafiltration for the removal of patulin from apple juice. The average losses of patulin were 39% and 25% for conventional clarification and filtration, and ultrafiltration, respectively. Washing and handling appeared to be the most critical steps in removing patulin from apples since up to 54% could be removed using high-pressure water spraying. Received: 22 January 1998 / Revised version: 21 April 1998     

Physicochemical and sensory properties of purple Brazilian cherry (Eugenia uniflora,L.) foams

The objective of this work was to characterise the foams of purple Brazilian cherry (Eugenia uniflora L.) pulp made with different additives, aiming at foam‐mat drying. Characterisation was made through analyses of moisture, pH, acidity, soluble solids, density, water activity, colour, total and reducing sugars, protein and ashes. Drying was done at 55 °C for 2 h. Dried Brazilian cherry juice powder was rehydrated for acceptance test. It is concluded that the physicochemical characterisation of fresh Brazilian cherry pulp was satisfactory and was in accordance with the Brazilian standards for agro‐industrial products. Albumin was the best foaming agent that produced a good‐quality powder in a short period. The foam‐mat drying of Brazilian cherry pulp using albumin and Superliga^® (Duas Rodas Industrial ltda, Santa Catarina, Brazil) as foaming agents produced a powder with good physicochemical properties and sensory quality and most preferred juice.     

EFFECT OF COMMERCIAL PROCESSING STAGES OF APPLE JUICE ON PATULIN, FUMARIC ACID AND HYDROXYMETHYLFURFURAL (HMF) LEVELS

The effects of different stages of commercial apple juice production on the patulin, fumaric acid and hydroxymethylfurfural (HMF) contents of apple juice were investigated. Heat treatment and activated charcoal were effective for the reduction of patulin. The average reduction of patulin were 13.4% and 22.9% for heat treatment and activated charcoal, respectively. Statistical analysis showed no significant differences (P<0.05) in the presence of fumaric acid between different treatments. Filtration and heat treatment caused an apparent increase in the HMF content, while activated charcoal caused a decrease. The average increments of HMF were 40.4% and 38.0% for separation and heat treatment, respectively, while the average reduction of HMF was 23.7% for activated charcoal. Spiking of samples with known amounts of patulin and fumaric acid revealed respective recovery rates of 96.4% and 95.9%.     

Continuous production of very enriched fructose syrup by the conversion of glucose to ethanol from glucose-fructose mixtures in an immobilized cell reactor

The yeast Saccharomyces cerevisiae ATCC 36859, which preferentially utilizes glucose in glucose-fructose mixtures, was immobilized and used for the continuous production of very enriched fructose syrup. A syrup containing fructose as 99% of the reducing sugars was produced from a 10.1% w/v glucose and 9.8% w/v fructose mixture at a dilution rate of 0.106 h⁻¹. Later in this process when the dilution rate was increased to 0.366 h⁻¹ the ethanol productivity was 12.7 g 1⁻¹ h⁻¹. This is 16% less than the value attained in a similar medium containing only glucose as the carbohydrate. The fructose content was also increased from 55 to 95% of the reducing sugars in a food grade mixture of high fructose corn syrup and Jerusalem artichoke juice. Purification of the product with activated carbon and ion-exchange resin produced a stable, colourless and very enriched fructose syrup suitable for human consumption.     

Extraction and characterisation of meat from the claws of freshwater crayfish using dense media

The purpose of this study was to investigate the effectiveness of a two‐phase (flotation and filtration) separation of claw meat from the shell of freshwater crayfish using dense media, and to evaluate modifications to physicochemical and functional properties of the recovered meat, which could be subsequently incorporated in value‐added commodities. The media used were 10% (w/w) brine, 30% glucose syrup and a 30:70 ratio of glucose syrup to 2, 5 and 10% brine, with specific gravities ranging from 1.08 to 1.16. Extraction recovery of food‐grade mince ranged between 33.3 and 43.5%, which compared favourably with that of the control (hand‐picked meat, 33.2%). Compared with the control, the meat recovered from the two phases (treated meat) was significantly firmer in texture, lower in moisture and pH and less bright in colour. Meat salt content was reflective of the salt concentration in the recovery medium used. The treated meat also had a significantly lower apparent emulsification (20%) and water‐binding (60%) capacity than the hand‐picked meat. Comparing the two extraction phases, filtration‐phase meat had a significantly lower emulsion capability, was less firm and was brighter in colour than flotation‐phase meat. © 2000 Society of Chemical Industry     

氢氧化镁应用于亚法糖汁澄清过程的初步研究

初步研究了氢氧化镁应用于亚法糖汁澄清在清净效果方面的情况。通过与传统的亚法澄清对比 ,对氢氧化镁的澄清效果在沉降速度、过滤速度、清汁简纯度、清汁pH、清汁色值的结果进行了分析。