Comparative stability of aspartame and neotame in yoghurt

The comparative stability of aspartame and neotame was monitored in yoghurt during its processing, fermentation and storage. A solid‐phase extraction method was suggest changing it to developed for the isolation of aspartame and neotame. Pasteurisation (85 °C/30 min) resulted in approximately 47% and 3% loss of aspartame and neotame, respectively. During fermentation, 3% loss of aspartame was observed, but no loss of neotame. There was no significant effects on the stability of either aspartame or neotame during storage (4–7 °C/15 days). The results indicated that neotame was more stable than aspartame under both pasteurisation and fermentation conditions; however, during storage, both sweeteners exhibited excellent stability.     

Chemical stability of extra-virgin olive oil added with oregano essential oil

Extra virgin olive oil is highly consumed and well known for its nutritional and health benefits. However, it is fatty food highly susceptible to lipid oxidation. The objective of this study was to evaluate the preserving effect of oregano (Origanum vulgare L. spp vulgare called "oregano compacto") essential oil on physical and chemical properties in extra virgin olive oil during storage. Oregano essential oil composition was analyzed by GC-MS. This essential oil was added into extra virgin olive oil at 0.05%. The samples were stored in 3 different conditions: darkness, light exposure, and temperature (60 °C). Chemical indicators of lipid oxidation (peroxide value, p-anisidine value, conjugated dienes, free fatty acidity, and carotenoid and chlorophyll contents) were measured. High content in carvomenthol (22.52%), terpinolene (19.77%), thymol (13.51%), and γ-terpinene (10.30%) were detected in oregano essential oil. Olive oil samples without oregano essential oil stored at 60 °C and exposure at artificial light had the highest peroxide values during storage. Higher p-anisidine and K232 values after day 7 of storage were detected in temperature, darkness, and light exposure treatments. Light treatment was the main factor that degraded chlorophyll causing loss of color. The highest chlorophyll content (3.87 mg/kg) was observed in olive oil with essential oil at the end of storage. In general, olive oil samples added with oregano essential oil had lower peroxide, conjugated dienes, and p-anisidine values and higher chlorophyll and carotenoid contents during storage. Oregano essential oil retards lipid oxidation process in olive oil prolonging its shelf life. PRACTICAL APPLICATION: Oregano essential oil was and is used with the purpose of flavoring and aromatizing food. This essential oil due to its composition has shown antioxidant activity. Synthetic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are thought to be promoters of carcinogenesis. Extra virgin olive oil is widely consumed because of its nutritional benefits and sensory properties which are very important to be preserved in the product. In this study, the oregano essential oil showed remarkable antioxidant activity in olive oil. Therefore, this essential oil could be considered for the industry as natural antioxidant not only to be used in olive oil but also in other fatty food products to substitute synthetic ones.     

Use of berry pomace to replace flour,fat or sugar in cakes

Pomace from fruit juice production is a by‐product with a high fibre and bioactive compound content. It is commonly used as animal feed, so using it in food brings added value. The present study assessed the effect of using black currant and aronia pomace to replace either part of the flour, fat or sugar in sponge cakes. Batters in which sugar was replaced showed the highest viscosity. On the other hand, flour replacement led to batters with the lowest viscosity and gave place to softer cakes with fewer but larger‐sized air cells. Sugar replacement conferred greater hardness and a larger number of small air cells. In general, fat replacement gave rise to intermediate crumb texture and structure properties in comparison with flour and sugar replacements. In vitro starch digestion showed that the flour‐replaced sponge cakes possessed the lowest hydrolysis index and glycaemic index values. The sponge cakes with the different replacements were well accepted by consumers, who expressed a high level of buying intention for all of them.     

Vitamin C stability in encapsulated green West Indian cherry juice and in encapsulated synthetic ascorbic acid

Kinetic studies on the degradation of vitamin C and nonenzymatic browning of green West Indian cherry juice and synthetic ascorbic acid, encapsulated in maltodextrin DE20 and a mixture of this with gum arabic, were carried out at different temperatures (15, 25, 35 and 45 °C). Vitamin C degradation followed the first‐order and nonenzymatic browning a zero‐order kinetic model. At higher storage temperatures the formulation containing a mixture of maltodextrin and gum arabic (3:1) was the most effective for vitamin C protection. An increase in storage temperature showed a greater impact on the degradation of synthetic vitamin C than on that of the green West Indian cherry juice. These differences could be due to the presence of phenolic compounds with antioxidant activity, protecting the vitamin C. Copyright © 2006 Society of Chemical Industry     

面粉贮藏过程中铁化学形式的变化

将各种铁源加到面粉中,测定贮藏过程中铁化学形式的变化。乙二胺四乙酸铁钠和元素羰基铁粉在贮藏过程中变化不大,而硫酸亚铁和柠檬酸铁铵在贮藏过程中绝大部分变成了不溶性铁。      

Enzymic hydrolysis of fish offal without added water

A significant finding of this work, concerned with the hydrolysis of cod (Gadus morhua) offal with papain (0·05% of fish offal, w/w, wet basis, at 65°C), was that the rate of hydrolysis was not dependent on the concentration of substrate in the range of 10–20% w/w dry matter. This, together with the fact that the ‘viscosity’ of the minced offal was reduced considerably at 65°C, made it possible to carry out the hydrolysis without the addition of water. Consequently, the major factors influencing processing and capital investment costs, namely energy for water removal, power for mixing and equipment size, could be substantially reduced. It was also found that enzyme inactivation after hydrolysis could be carried out by heating up to only 80°C and maintaining that temperature for 12 min; this treatment reduced the enzyme activity to 1% of its original value.     

Oxidative stability of yogurt with added lutein dye

This study evaluated the effect of adding lutein dye on the oxidative stability of yogurt during 35 d of refrigerated storage, in the presence and absence of light. Yogurts manufactured without and with the equivalent of 1.5 mg of lutein in 120 g of the final product were characterized for their total carotenoid and riboflavin contents, and the behaviors of both riboflavin and lutein were monitored during storage. A decrease in riboflavin content occurred, with concurrent appearance of its derived-oxidation products in the yogurts without added lutein and exposed to light during storage. The yogurts with added lutein dye showed constant lutein and riboflavin contents throughout storage both for the samples stored under light and for those stored in the dark. Yogurts (120 g) with the addition of 0.5, 1.5, and 2.5 mg of lutein dye were evaluated for their sensory acceptance, and the statistical analysis showed no differences between the samples for the attributes of aroma and flavor. These results indicate that the added lutein remained stable throughout the storage period and conferred protection for the riboflavin against photooxidation, preserving the quality of the yogurts.     

无蔗糖胡萝卜软糖的研制

本文介绍了无蔗糖胡萝卜软糖的生产工艺。以新鲜胡萝卜为原料,在单因素试验和正交试验基础上,以蛋白糖、山梨糖醇、麦芽糊精等替代蔗糖研制出具有营养保健作用的胡萝卜软糖。     

无糖豆渣饼干的制作

在传统糕点中添加不同比例的豆渣进行探索性研究，通过正交实验和品评实验，确定了生产原味、无糖豆渣饼干的最佳豆渣添加量及最佳工艺条件。     

微胶囊化薄荷油的制备及其热稳定性研究

以β-环糊精（β-CD）为壁材、薄荷油为芯材制备微胶囊化薄荷油。采用正交试验对β-CD包合薄荷油工艺进行优化，得到最佳工艺条件为：芯壁比1：8（W：W）、反应时间4h、反应温度50℃，微胶囊化产率为93．16％，薄荷油包埋量为10．35％（W：W）。采用热重分析法研究了薄荷油在微胶囊化前后的热稳定性，薄荷油经微胶囊包埋后，微胶囊囊壁阻止了薄荷油在受热情况下的挥发损失，从而使薄荷油的热稳定性大大提高。分别将薄荷油及微胶囊化薄荷油加入曲奇饼干中，感官评定结果显示：添加微胶囊化薄荷油的薄荷味曲奇饼干比直接添加薄荷油的产品具有更高的薄荷风味强度。     

Studies on interaction between stevioside,liquid sorbitol,hydrocolloids and emulsifiers for replacement of sugar in cakes

Studies were carried out on the replacement of sugar with stevioside and liquid sorbitol (SO); addition of hydrocolloids, emulsifiers with and without 10% debittered fenugreek seed powder (DFSP) to a mixture of stevioside and SO on the rheological, microstructural and quality characteristics of cake. Experimental data showed that addition of sugar increased the amylograph viscosity of wheat flour paste during heating and cooling while SO at different percentages decreased these viscosities, however addition of combination of hydrocolloid (xanthan, XA) and emulsifier (polysorbate-60, PS-60) increased the viscosity of wheat flour paste with 100% SO. Addition of combination of XA + PS-60 improved distribution pattern of air cells, increased batter viscosity, cohesiveness, overall quality score of cake with 100% SO and allowed incorporation of DFSP to improve the functional characteristics of cake. Evaluation of composition of developed cake showed negligible sucrose content, perceptible fenugreek flavor and increased dietary fiber as against cake with sugar.     

护色剂对红曲红色素稳定性的研究

开发了一种新型的护色剂,对天然色素的光稳定性具有非常显著的提高效果,在不改变色素结构的情况下能够将色素的残存率提高数倍以上,实验以红曲红色素为例考察护色剂的效果,确定了护色剂的最佳添加量为0.0001%(m/v),最佳pH7。     

甘草提取物对乳化猪油氧化稳定性的影响 及乳化猪油在蛋糕中的应用

为促进乳化猪油在烘焙食品中的应用,分析了甘草提取物及其组分（甘草酸、光甘草定）对乳化猪油氧化稳定性的影响,同时将乳化猪油应用于蛋糕中,研究了乳化猪油的含油量对蛋糕品质的影响。结果表明：甘草提取物及其组分均能大幅延缓乳化猪油的氧化酸败,其中甘草提取物的延缓效果最显著;含有0.02%甘草提取物的乳化猪油（含油量80%）在40 ℃下储藏28 d,其酸值、过氧化值、硫代巴比妥酸值与空白组相比分别下降了72.53%、47.45%、62.98%;含油量80%的乳化猪油制备的蛋糕的膨胀体积与含油量50%的乳化猪油制备的蛋糕相比增加了99.75%,硬度、弹性和咀嚼性分别降低了21.37%、14.58%、31.74%,但各指标均比猪油制备的蛋糕的差。综上,乳化猪油具有替代猪油应用于蛋糕制备的潜力,但仍需进一步深入探究乳化猪油组分与蛋糕中其他组分间的相互作用,进而提高蛋糕品质。     

Rheological quality and stability of yog-ice cream with added inulin

Research was conducted to examine the effect of inulin on the rheological and textural characteristics of yog-ice cream desserts in relation to their sensory attributes. Addition of inulin to yog-ice cream was shown to increase viscosity of the yogurt-ice cream mix and increase hardness of the resulting yog-ice cream. Meltdown characteristics of the yog-ice creams demonstrated a clear relationship between increased oligosaccharide levels and improved melting properties.     

Light stability of spray-dried bixin encapsulated with different edible polysaccharide preparations

Bixin was encapsulated by spray-drying with gum arabic or maltodextrin, and the stability was evaluated in aqueous solution both under illumination or in the dark at 21 °C. The microcapsules containing emulsifier, such as gum arabic or maltodextrin + Tween 80, showed the highest encapsulation efficiency, respectively 86% and 75%, less superficial imperfections and higher stability than bixin encapsulated with maltodextrin alone or blended with sucrose. The kinetic behavior of bixin photodegradation in all encapsulated systems was composed by two first-order decays, due to the presence of bixin outside and inside the microcapsules. Bixin encapsulated with gum arabic was 3 to 4 times more stable than that encapsulated with maltodextrin. In all systems, greater bixin stability (<two orders of magnitude) was observed in the dark than under illuminated conditions. In addition, 10 times greater bixin stability was observed for encapsulated solutions as compared to the non-encapsulated systems in the absence of light.     

新型无糖苦瓜酸奶的研制

研究了具有营养保健功能的无糖苦瓜酸奶的加工工艺,结果表明:以鲜苦瓜为原料,用100mg/kg葡萄糖酸锌作为护色剂、1%-β环状糊精作为苦味包埋剂,可制得质量良好的苦瓜汁;采用苦瓜汁∶鲜牛奶=37∶的原料配比、阿斯巴甜0.05%、复合稳定剂0.15%,将保加利亚乳杆菌和嗜热链球菌以11∶混合作为发酵剂进行发酵、接种量3%、发酵温度42℃、发酵时间5h等工艺条件,可得到品质风味优良的新型无糖苦瓜酸奶。     

Pink grapefruit lycopene encapsulated in alginate-based beads: stability towards freezing and drying

Alginate-based beads containing lycopene extract were produced with the addition of various sugars and biopolymers. In present work, lycopene stability was studied on beads subjected to thermal treatments: continuous freezing (−18 °C, 30 days), four freezing/thawing (f/t) cycles, dehydration by vacuum- and freeze-drying. The progress of crystallisation was assessed using transversal relaxation times (T₂) obtaining isothermal curves at different temperatures. Alginate beads containing trehalose with β-cyclodextrin and arabic gum retained a high lycopene content (>80%) after freezing and drying, regardless of the freezing or drying method. Instead, beads containing only alginate showed sever lycopene decrease in all cases. Continuous freezing affected both lycopene content and stability to a higher extent than f/t cycles. Isothermal studies revealed the lower amount of crystallised water in beads containing trehalose (with or w/o other excipients), reducing also the time to arrive at the 50% of crystallisation during freezing.     

Physical stability of emulsion encapsulated in alginate microgel particles by the impinging aerosol technique

Emulsion filled alginate microgel particles can be applied as carrier systems for lipophilic actives in pharmaceutical and food formulations. In this study, the effects of oil concentration, emulsifier type and oil droplet size on the physical stability of emulsions encapsulated in calcium alginate microgel particles (20–80 μm) produced by a continuous impinging aerosol technique were studied. Oil emulsions emulsified by using either sodium caseinate (SCN) or Tween 80 were encapsulated at different oil concentrations (32.55, 66.66 and 76.68% w/w of total solids content). The emulsions were analysed before and after encapsulation for changes in emulsion size distribution during storage, and compared to unencapsulated emulsions. The size distribution of encapsulated fine emulsion (mean size ~ 0.20 μm) shifted to a larger size distribution range during encapsulation possibly due to the contraction effect of the microgel particles. Coarse emulsion droplets (mean size ~ 18 μm) underwent a size reduction during encapsulation due to the shearing effect of the atomizing nozzle. However, no further size changes in the encapsulated emulsion were detected over four weeks. The type of emulsifier used and emulsion concentration did not significantly affect the emulsion stability. The results suggest that the rigid gel matrix is an effective method for stabilising lipid emulsions and can be used as a carrier for functional ingredients.     

Changes in protein function of sardines stored in ice with and without added salt

Summary In some Southern European countries, it is common practice to add varying quantities of salt to the ice used to cool and preserve the sardine, so as to improve its texture and allow longer storage. Considering that sardine stored in this way may be used in the manufacture of a number of different products, the effects of salt in the ice were investigated, with reference to functional properties such as protein solubility (PS), emulsifying capacity (EC) and apparent viscosity ( _app). The added salt significantly increased (P0.05) the salt content of the muscle, bringing about an initial reduction in protein solubility and a decrease in EC and _app as storage time progresses. In the absence of salt, these two functional properties remain constant or are enhanced. Thus, although salt permits prolonged storage, protein functions are reduced in sardine treated in this way to that in non-salted sardine, making the salted sardine is less suitable for subsequent use in different technological processes.

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Veränderungen der Funktionseigenschaften der Proteine in Sardinen bei Eis-Lagerung mit oder ohne Salz

Zusammenfassung In einigen Ländern Südeuropas ist es üblich, verschiedene Mengen an Salz in das erforderliche Eis zu geben für die Konservierung der Sardinen. Dadurch wird die Textur verbessert und die Lagerzeit verlängert. Die so behandelten Sardinen kann man zur Herstellung verschiedener Produkte verwenden. Aus diesem Grund sollte in der Untersuchung festgestellt werden, ob Salz die Eigenschaften der gekühlten Sardinen beeinflußt, und zwar die Proteinlöslichkeit, die Emulsionsfähigkeit und die scheinbare Viscosität. Der Grund dieser Untersuchung ist die Eignung des Fleisches für gewisse technologische Prozesse zu prüfen. Das Salz im Eis vermindert am Anfang die Proteinlöslichkeit; bei zunehmender Lagerzeit nimmt die Emulsionsfähigkeit und die scheinbare Viscosität ab. Wenn Salz im Eis nicht vorhanden ist, dann bleiben diese Eigenschaften unverändert oder sie erhöhen sich. Als Endergebnis verlängert das Salz die Lagerzeit, und gleichzeitig wird die Protein-Funktion stärker reduziert als bei nicht behandelten Sardinen. Deswegen sind die unbehandelten Sardinen für technologische Prozesse weniger geeignet.

     

壳核式海藻酸钠鱼油微球的制备及氧化稳定性研究

目的:本研究旨在考察新型鱼油微球的制备方法以及初探其氧化稳定性。方法:利用电共挤出技术制备新型\