超声波促进高纤椰果发酵的研究

为了提高高纤椰果发酵产量,在浅层静态发酵过程中尝试加载超声波,研究了超声波处理条件对高纤椰果发酵的影响。结果表明,适宜的超声波处理条件对高纤椰果发酵有促进作用,利用超声波(400 W,28 kHz)从发酵48h开始进行处理,每次处理时间为180 s,每隔1.5 h处理1次,发酵240 h,纤维素干重可达到1.88 g,比空白实验提高了20.5%。     

“Nata Puree,” a Novel Food Material for Upgrading Vegetable Powders,Made by Bacterial Cellulose Gel Disintegration in the Presence of (1,3)(1,4)-β-Glucan

Pulverization is a potentially powerful solution for the resource management of surplus- and non-standard agricultural products, maintaining their nutritional values for long and ensuring their homogeneity, whereas their original textures could disappear to narrow the application ranges. Therefore, new technologies should be developed for reconstructing the powders to provide them with new physical characteristics. Herein, we developed a novel food material, nata puree (NP), by nata de coco (bacterial cellulose gel) disintegration with a water-soluble polysaccharide using a household blender. The process worked well with (1,3)(1,4)-β-glucan (BGL) as the polysaccharide, which could be substituted with barley extract. Lichenase treatment of the NP dramatically modified its physical properties, suggesting the importance of the BGL polymeric forms. NP exhibited distinct potato powder and starch binding activities, which would be attributed to its interactions with the cell wall components and a physical capture of powders by the NP network, respectively. NP supplementation into the potato paste improved its firmness and enabled its printable range shift for 3D food printing to a lower powder-concentration. NP also promoted the dispersion of powders in its suspension, and designed gelation could also be successfully performed by the laser irradiation of an NP suspension containing dispersed curdlan and turmeric powders. Therefore, NP could be applied as a powder modifier to a wide range of products in both conventional cooking, food manufacturing, and next generation processes such as 3D food printing.     

Coconut water as a potential resource for cellulose acetate membrane preparation

BACKGROUND: Cellulose acetate membranes are frequently used for pressure‐driven membrane processes. The aim of this work was to prepare cellulose acetate membranes from nata‐de‐coco using coconut water as starting material. The use of this lignin‐free material will certainly minimize the use of chemicals usually needed in the traditional pulps and substitute for the use of wood, which helps prevent global warming and preserves nature as well. RESULTS: Coconut water was fermented by Acetobacter xylinum for 6 days to produce nata‐de‐coco, which was then acetylated to produce cellulose diacetate with an acetyl content of 39.6%. Fourier transform infrared analysis showed characteristic peaks for the acetyl group at 1748 and 1236 cm^?1. The resulting membranes made from the hydrolysis product showed a water flux of 210.5 L m^?2 h^?1 under an applied pressure of 2 kg cm^?2 while the rejection coefficients of dextran T‐500 and T‐2000 solutions were 78 and 93.7%, respectively. CONCLUSION: Coconut water has a potential to be used in the fabrication of membranes by converting it to nata‐de‐coco and then to cellulose diacetate which gives an added value to its original nature. It is also highly competitive compared to the traditional pulps, by which acetylation decreases the degree of crystallinity of nata‐de‐coco resulting in higher membrane permeability. Copyright © 2007 Society of Chemical Industry     

Fermentation of Monascus purpureus on Bacterial Cellulose-nata and the Color Stability of Monascus-nata Complex

Nata, a bacterial cellulose produced by Acetobacter aceti ssp. xylinum , was colored by means of fermentation with Monascus purpureus. Scanning electron microscopy (SEM) observations showed that the Monascus mycelium could grow through the cellulose network of nata. Rice powder as a major carbon source and monosodium glutamate (MSG) as a nitrogen source gave an appealing coloration after 12 d of fermentation at 30 °C. Compared to dyed nata, the color of the Monascus -nata complex had better resistance to washing, heat, freezing, acidification, and alkalization. A 66.1% decolorization was found under irradiation with 366 nm ultraviolet light after 36 h. The Monascus -nata complex has the potential to be a new vegetarian foodstuff.     

醋酸菌发酵法缩短椰果生产周期技术研究

椰果是利用醋酸菌发酵制成的一种纤维多糖。作为一种新型产品,其生产规模较小。要提高椰果出品率,缩短凝固成型周期是关键。在椰果生产中,基础培养基的组分与其生产周期密切相关。通过研究发酵基础培养基中各组分对椰果生产周期的影响,得到醋酸发酵法缩短椰果凝固成型的最佳发酵基础培养基配方为:蔗糖45g/kg,(NH4)2SO44g/kg,MgSO40.2g/kg,KH2PO42g/kg,琼脂0.33g/kg,NaAc1.33g/kg,FeSO40.005g/kg,C2H5OH0.05g/kg,死菌液10g/kg,pH=4.0。在此基础上,进一步研究了菠萝水与椰子水混合配比(体积比)对椰果生产周期、品质及经济性的影响,综合考虑后确定菠萝水与椰子水的比例为6∶1。利用优选出的培养基进行发酵,大大缩短了椰果成型周期。     

响应面分析法优化干椰纤果制备工艺

通过单因素及响应面试验探讨羧甲基纤维素钠(CMC)真空渗透条件和热风干燥条件对椰纤果的复水性、复水后的质构等的影响。结果表明：采用CMC真空渗透处理可以改善干椰纤果的复水比、复水后的硬度和弹性。影响干椰纤果复水性质的因素主要是CMC质量分数、固液比、干燥温度、真空渗透时间,干椰纤果制备的最佳工艺条件为：CMC质量分数0.90%、固液比1:2、真空渗透时间4.5h、干燥温度60℃。     

纳塔产生菌的分离鉴定和发酵特性研究

纳塔(nata)是一种由微生物经液态发酵形成于液体表面的凝胶膜状物[1],主要成分是纤维素[2,3]。目前在台湾和大陆的商品名叫“椰果”、“高纤椰果”,因其外形极象嫩椰肉,且最常用的发酵原料是椰子水。由于它持水性好,具有独特的凝胶状半透明质构,其最广泛的应用是加工成各?..     

Influence of Bacterial Cellulose (nata) on the Physicochemical and Sensory Properties of Frankfurter

The physicochemical and sensory characteristics of pork frankfurters containing different levels (10% to 30%) of bacterial cellulose (nata) were evaluated. Emulsion stability of the raw meat batter decreased with the addition of nata. For nata‐added treatments, increasing levels of nata in frankfurters resulted in decreased textural hardness and shear values. Sensory results indicated that N10 and N20 had significantly higher firmness scores than N30 and control. However, juiciness score did not differ for all treatments. Incorporation of nata at lower levels (10% to 20%) did not have detrimental effects on the physicochemical, textural, sensory, and microbiological properties of regular‐fat frankfurters. Addition of a higher level (30%) of nata essentially produced comparable sensory properties to the control, but lower levels of nata in frankfurters yielded higher sensory firmness and instrumental hardness values. Based on the composite results, manufacture of regular‐fat frankfurter containing 10% to 20% high‐fiber nata resulted in product quality comparable to the control.     

椰子纳塔发酵条件研究

研究了一株醋酸杆菌（Ａｃｅｔｏｂａｃｔｅｒｓｐ．）在椰子水培养液中发酵产生纳塔（ｎａｔａ）的适宜工艺条件：蔗糖７％,ＮＨ４Ｃｌ０．４％,ＫＨ２ＰＯ４０．２％,ＭｇＳＯ４０．０２％,ＣａＣｌ２０．０２％,ＦｅＳＯ４０．０００５％（Ｗ／Ｖ）,酵母膏０．０５％,柠檬酸０．０２％,椰子水５０％～１００％（Ｖ／Ｖ）,ｐＨ４．０,用大口容器盛装,３０℃静置培养１４～１８ｄ。在此条件下,于５００ｍｌ烧杯中发酵１６ｄ,最高可收获１８２ｇ重,３．３ｃｍ厚的纳塔,其外观和品质均符合纳塔食品的加工要求。     

Quality Characteristics of Chinese-style Meatball Containing Bacterial Cellulose (Nata)

ABSTRACT: The physicochemical, textural, and quality characteristics of Chinese-style meatball (20% fat) containing varying levels of bacterial cellulose (nata) were evaluated. Cooking losses of nata-containing Chinese-style meatballs were higher than those of control (containing no nata and 20% fat [C20]). Raw nata-added batter had higher water-holding capacity than control, but the pattern was reversed after cooking. N10 (10% nata) and C20 had the highest springiness scores. Textural hardness and shear-force value were significantly higher for C20, but both attributes for nata-added treatments decreased with increasing nata levels. Addition of 10% nata to Chinese-style meatballs produced products with acceptable textural and sensory qualities. Nata showed potential as a functional ingredient in Chinese-style emulsified meat products such as Chinese-style meatballs.