Vitamin A stability in triple fortified extruded,artificial rice grains containing iron,zinc and vitamin A

Multi‐micronutrient‐fortified rice could be an effective and sustainable approach to combat micronutrient deficiencies. We produced hot‐extruded artificial rice grains fortified with 10 mg iron (as micronised ground ferric pyrophosphate), 5 mg zinc (as oxide, sulphate or carbonate) and 750 μg vitamin A/g [as retinyl palmitate (RP)] and measured RP stability. The rice was designed to be mixed 1:200 with natural rice. Mean RP losses were 5.3% during extrusion, 28.5% during storage and 9.8% during cooking. Storage losses after 18 weeks at 30 °C in plastic packages exposed to light were ca 40% with iron and zinc causing no further losses. In aluminium packages (no light), mean RP losses were ca 20%. Iron, but not zinc, increased RP degradation. Zinc sulphate increased the negative effect of iron. The relatively good stability of RP during hot extrusion can be explained by the closed surface and dense nature of the artificial grain protecting RP from oxidation.     

Bioavailability and storage stability of vitamin A fortificant (retinyl acetate) in fortified cookies

Vitamin A deficiency is one of the major nutritional deficiencies affecting population in developing regions. In Pakistan, 60% of the child deaths are due to diarrhea and respiratory infection, which are associated with vitamin A deficiency. This study was to assess the bioavailability and stability of vitamin A fortificant in cookies fortified with retinyl acetate. Cookies fortified with Vitamin A (retinyl acetate) were manufactured and physically, chemically and sensorial analyzed. Efficacy studies were carried and Serum retinol concentrations were measured to assess the bioavailability of Vitamin A (retinyl acetate), different organ weights were also measured to check the effects of Vitamin A (retinyl acetate) on organ weights and body growth. The treatment T₄ containing (257.85 μg) 45% RDA fortification level of retinyl acetate was judged best considering, physical, chemical and sensory characteristics. Baking losses were lowest in T₄. Efficacy study revealed that Serum retinol concentrations were 125.19 μg/dl in control group and it was raised to 148.64 μg/dl in T₄. Liver, lungs, left kidney, right kidney, heart, spleen, brain, left testicles and right testicles increased in their weights when fed with vitamin A fortified diet as compared to control. Exceptions were only brain and spleen, in spleen it remained stable and brain weight reduced as compared to control. Fortification of cookies with 257.85 μg (45% RDA) of retinol acetate improved nearly all quality attributes and through efficacy studies it was concluded that vitamin A significantly affects growth and body functioning of rats. Concludingly cookies fortified with 257.85 μg of retinol acetate can be used effectively to overcome vitamin A deficiency in the children.     

UHT乳贮存过程中V_A和V_C的变化

选择市场上3种UHT乳通过25、37℃和45℃恒温进行贮存温度加速实验比较VA和Vc含量的变化。结果表明,对于VA在3个不同的贮存温度下随贮存时间延长均不断下降,下降速率最高为45℃贮存,最高下降率达到82%,且随贮存温度升高下降越快;贮存中Vc含量变化在3种产品间无差异,且随贮存时间延长略下降,不同贮存温度间变化无差异。对于贮存中UHT乳的品质变化可以选择VA作为指标之一。     

Short communication: Production of cottage cheese fortified with vitamin D

The availability of alternative food products fortified with vitamin D could help decrease the percentage of the population with vitamin D deficiency. The objective of this study was to fortify cheese with vitamin D. Cottage cheese was selected because its manufacture allows for the addition of vitamin D after the draining step without any loss of the vitamin in whey. Cream containing vitamin D (145 IU/g of cream) was mixed with the fresh cheese curds, resulting in a final concentration of 51 IU/g of cheese. Unfortified cottage cheese was used as a control. As expected, the cottage cheese was fortified without any loss of vitamin D in the cheese whey. The vitamin D added to cream was not affected by homogenization or pasteurization treatments. In cottage cheese, the vitamin D concentration remained stable during 3 weeks of storage at 4°C. Compared with the control cheese, the cheese fortified with vitamin D showed no effects of fortification on cheese characteristics or sensory properties. Cottage cheese could be a new source of vitamin D or an alternative to fortified drinking milk.     

Viscous and thermal behaviour of vitamin A and iron‐fortified reconstituted rice

The viscous and thermal behaviour of five types of micronutrient‐fortified reconstituted rice premixes extruded at pre‐optimised extrusion conditions (36% moisture content, 150 rpm screw speed and 89 °C barrel temperature) have been investigated using rapid visco analyser (RVA) and differential scanning calorimetry (DSC). The highest peak viscosity (1279 cP), lowest gelatinised starch percentage (16.32) and highest enthalpy of gelatinisation (8.2 J g^?1) were recorded in rice premix fortified with retinyl palmitate and micronised ferric pyrophosphate. The scanning electron microscopic analysis (SEM) also revealed that reconstituted rice premix fortified with iron (micronised ferric pyrophosphate) and retinyl palmitate was in closer resemblance to that of natural rice than any other reconstituted rice premix. The work demonstrated that vitamin A‐ and iron‐fortified reconstituted rice with meso/micro structure and pasting behaviour close to that of natural rice can be produced using retinyl palmitate and micronised ferric pyrophosphate as vitamin A and iron source, respectively.     

强化食用油中维生素A的检测

本文提出一种利用三氯乙酸氯仿溶液与维生素A反应的分光光度法 ,检测强化食用油中维生素A。反应产物在62 0nm有最大吸收 ,在 0 .15～ 3 .3 5μg/ml范围内吸光度与浓度呈线性关系。回收率在 90 .3 %以上 ,RSD小于 3 .5 %。样品中低于1.0mg/ml的维生素D2 和 0 .8mg/ml的β-胡萝卜素不干扰测定。测定强化食用油中的维生素A的结果与国标得到的结果基本一致     

贮存温度和贮存时间对复原乳稳定性的影响

研究了贮存温度和贮存时间对复原乳的pH值、流变特性、粒径、乳析率和离心沉淀率的影响,在此基础上分析了贮存过程中乳浊液粒径与乳析率、离心沉淀率之间的相关性。结果表明:随着贮存温度的升高,复原乳的pH值与表观黏度逐渐降低,而随着贮存时间的延长,二者均先升高后降低,其中25℃和37℃下贮存在第15天时达到最大值,而55℃下贮存在第7天时达最大值;贮存过程中乳浊液顶部粒径d4,3与乳析率有较好的相关性(P<0.05),二者均随着贮存温度的升高和贮存时间的延长而增大;贮存过程中乳浊液底部粒径d4,3与离心沉淀率有很好的相关性(P<0.05),二者随着贮存温度的升高先增大后减小,在37℃时达最大值,随着贮存时间的延长均有所增大。     

蔗糖酯对超级棕榈液油储藏过程中耐寒性的影响

为改善油脂储藏过程中的耐寒性,利用添加不同类型且不同量的蔗糖酯对超级棕榈液油在20℃储藏过程中其耐寒性的变化进行研究.耐寒性以样品在20℃储藏过程中的5℃冷冻试验时间、透明度和20℃储藏黏度的变化进行评判.结果表明:长碳链饱和脂肪酸棕榈酸和硬脂酸型蔗糖酯显著缩短了超级棕榈液油的5℃冷冻试验时间,长碳链不饱和脂肪酸油酸型蔗糖酯可明显延长超级棕榈液油的5℃冷冻试验时间(P＜0.05),而中碳链脂肪酸月桂酸型蔗糖酯和混合脂肪酸(棕榈酸、硬脂酸和油酸)型蔗糖酯也可延长超级棕榈液油的5℃冷冻试验时间,但其同时引起储藏过程中超级棕榈液油透明度的明显下降(P＜0.05);不同类型蔗糖酯对超级棕榈液油20℃恒温储藏过程中的黏度无显著影响(P＞0.05).     

Stability of vitamin A palmitate in cosmetic emulsions: influence of physical parameters

The aim of this work was to verify if a close relationship exists between the physical stability of an emulsion and the chemical stability of vitamin A palmitate included in it. Oil-in-water cosmetic emulsions with high viscoelastic properties were prepared, and their rheological behaviour was investigated in oscillatory conditions. The stability of each sample was verified in high-temperature stress conditions: periodical checks of physical parameters and chromatographic analysis of vitamin A were performed during storage. Results show that the chemical stability of vitamin A palmitate strictly depends on the physical stability of the formulation and in particular on the presence of a coherent gel-like structure in the external phase of the emulsion.     

馒头加工和贮藏过程中营养强化剂叶黄素酯的稳定性

为了探讨营养强化剂叶黄素酯在馒头加工和贮藏过程中的稳定性,通过叶黄素酯水溶性微囊粉添加于馒头中,分析馒头和面、压延、发酵、蒸制和储藏过程中总叶黄素酯、总叶黄素及其异构体的变化情况。结果表明:和面、压延和发酵对叶黄素酯的降解影响不显著,蒸制引起馒头中叶黄素酯含量下降明显;馒头加工过程对皂化测得的总叶黄素和全反式叶黄素保留率较高。叶黄素酯强化馒头在整个加工和储藏过程都伴随着叶黄素异构体的生成和含量变化,和面过程中生成了少量的13-顺式和13’-顺式叶黄素,压延、发酵过程13-顺式和13’-顺式叶黄素含量继续增加,蒸制引起13-顺式、13’-顺式叶黄素含量显著增加以及9-顺式叶黄素的生成。储藏过程中馒头中的叶黄素酯、皂化测得的总叶黄素和全反式叶黄素含量,及叶黄素顺式异构体含量均略有下降。      

Effects of sterilization, packaging, and storage on vitamin C degradation, protein denaturation, and glycation in fortified milks

Monitoring the nutritional quality of dietetic milk throughout its shelf life is particularly important due to the high susceptibility of some vitamins to oxidation, and the continuous development of the Maillard reaction during storage.The objective of this paper was to evaluate the vitamin C content and protein modification by denaturation and glycation on fortified milk samples (growth milks) destined for 1- to 3-yr-old children. The influences of the sterilization process, formulation, packaging, and storage duration at ambient temperature in the dark were studied. Vitamin C degradation was particularly influenced by type of packaging. The use of a 3-layered opaque bottle was associated with complete oxidation of vitamin C after 1 mo of storage, whereas in the 6-layered opaque bottle, which has an oxygen barrier, the vitamin C content slowly decreased to reach 25% of the initial concentration after 4 mo of storage. However, no significant effect of vitamin C degradation during storage could be observed in terms of Maillard reaction, despite the fact that a probable impact occurred during sterilization. Furosine content and the FAST (fluorescence of advanced Maillard products and soluble tryptophan) index-indicators of the early and advanced Maillard reaction, respectively-were significantly higher in the in-bottle sterilized milk samples compared with UHT samples, and in fortified milk samples compared with cow milk. However, after 1 mo, the impact of storage was predominant, increasing the furosine level and the FAST index at similar levels for the differently processed samples. The early Maillard reaction developed continuously throughout the storage period.In conclusion, only packaging comprising an oxygen and light barrier is compatible with vitamin C fortification of milk. Furthermore, short storage time or low storage temperature is needed to retard vitamin C degradation, protein denaturation, and development of the Maillard reaction.     

Degradation of Vitamin A Palmitate in Corn Flakes During Storage

ABSTRACT: The amounts of vitamin A palmitate lost and isomers formed in corn flakes fortified with a vitamin A palmitate were determined during storage at ambient (avg. 23 °C) and elevated (45 °C) temperatures. Two vitamin A palmitate isomers, 9-cis and 13-cis, were found. The initial vitamin A palmitate consisted of 5% of 13-cis and less than 1% of 9-cis with the remaining being all-trans. In corn flakes fortified with either a complete vitamin mixture or vitamin A palmitate only, the distribution of these compounds was nearly constant throughout storage irrespective of sample type and storage conditions. The rate constant and reaction kinetics on the degradation of vitamin A palmitate were also obtained. After 6–8 wk storage, more than 90% of vitamin A palmitate was lost in all samples except corn flakes fortified with complete vitamin mixture and kept at ambient temperature. This study showed that the loss of vitamin A palmitate fortified in corn flakes was substantial even at ambient temperature. The presence of other vitamins including vitamin A, B₁, B₆, B₁₂, C, and D reduced the loss of vitamin Abut the loss was still significant.     

Comparative study on the characteristics and oxidation stability of commercial milk powder during storage

The quality of milk powder can decrease during storage. In this study, the characteristics of 12 kinds of commercial milk powder from China were investigated. Changes in various indicators were tracked to comprehensively estimate the oxidation stability of different commercial milk powders. The components of the commercial milk powder were different. The percentages of milk fat, protein, and carbohydrates ranged from 9.8 to 28.5 g/100 g, 15.0 to 24.0 g/100 g, and 32.0 to 67.5 g/100 g, respectively. The water activities ranged from 0.2394 to 0.5286. The diameters of the milk fat globules in different commercial milk powder ranged from 13.99 to 41.09 nm. At the same time, the peroxide value of the control sample was low (≤0.14 mEq/kg). After 3 mo of storage, the peroxide values of some of the commercial milk powder increased significantly. The changes in the thiobarbituric acid values during storage did not follow a common trend. The contents of free fat in the different control samples were 0.21 to 1.67 g/100 g, and these values did not increase during storage. After 3 mo of storage, the hydroxymethyl furfural values and b color values of the different commercial milk powder reached their highest levels. The concentrations of typical oxidized flavor compounds in different commercial milk powder increased greatly with prolonged storage time. The level of hexanal was the highest, and the contents in all the samples ranged from 28.56 to 4,071.28 μg/kg after 6 mo of storage and from 5.91 to 6,281.37 μg/kg after 12 mo of storage. Free radicals were found in some of the stored milk powder, and these were shown as single peaks or multiple peaks. The ratios of the peak areas and masses reached 12.42 × 10⁶ to 14.26 × 10⁸. However, the presence of free radicals in the commercial milk powder was not consistent. The water activities and diameters of the fat globules in the commercial milk powder were highly correlated with their oxidation stabilities during storage.     

Comparison of the stability of palm olein and a palm olein/canola oil blend during deep‐fat frying of chicken nuggets and French fries

Stability of palm olein (PO) and a blend 50% palm olein/50% canola oil (POC) during deep‐fat frying at 180 °C of French fries (FF) or chicken nuggets (CN) was studied through the determination of physical and chemical parameters in the fresh and used oils. Degradation at the end of the study resulted in total polar compounds of 12–13.5% for PO and 11.5–14.5% for POC and viscosity of 65–123.3 cP for PO and 63–72.8 cP for POC. Lower peroxide values (5.33–6.32) were obtained for the blend (PO had 5.21–8.55). Food type affected colour parameters and p‐anisidine value of the oils. For CN, the lowest fat content and higher hardness were obtained when they were fried in PO. CN caused a faster deterioration in the oils, in comparison with FF, especially in POC. Gas chromatography allowed to observe differences in fatty acids composition for both used oils.     

Evolution of some physicochemical parameters of iodine fortified sunflower oil and margarine

Experimental research were effectuated to establish the modalities of incorporation of the molecular iodine in sunflower oil double refined and deodorised of autochthon production. It was established that the iodisation of sunflower oil may be considered as an admissible method, which allows the incorporation of a considerable amount of iodine (1–100 μg mL^?1) without modifying the physicochemical properties of the product. It should be noted that iodine value varied a little, even in the sample with a maximum content of iodine (1000 μg mL^?1), its values did not exceed permitted limit. Research of quality indices variation of iodised oil during product storage (3 months), demonstrated that only in the case of maximum concentration of iodine (1000 μg mL^?1) it was manifested a slight overcome of the maximum permitted limit caused by the free iodine presence. Iodised oil was used for the manufacture of iodised margarine in order to fortificate this product with iodine (1 μg iodine g^?1 margarine). Physicochemical indices (moisture and volatile substances, melting point, free fatty acids content) of iodised margarine did not differ from the characteristics of the product without iodine.     

Effect of dietary vitamin E supplementation and refrigerated storage on quality of rainbow trout fillets

Rainbow trout were fed a low vitamin E (200 mg/kg; LVE) or a high vitamin E (5000 mg/kg; HVE) diet for 9 wk to characterize the effect of vitamin E supplementation at 5000 mg/kg on fillet quality. Fish were sampled at 2, 3, 4, 5, 7, and 9 wk of the trial. Fillets were stored at 2 °C for 0, 7, and 14 d, and analyzed for pH, psychrotrophic counts, color, cook yield, shear force, crude fat and moisture content, α-tocopherol, fatty acid composition, and lipid oxidation. There was a significant feeding duration by fillet storage time interaction for psychrotrophic counts, crude fat content, cook yield, and shear force. Fillet L* value was not affected by diet, feeding duration or storage time. Fillet a* was lowest at 14-d storage, and b* values increased with fillet storage time. High vitamin E diet increased fillet α-tocopherol from 33 to 155 mg/kg. High vitamin E decreased palmitic acid and increased linoleic acid and omega-6 fatty acids. Feeding through 9 wk increased the relative proportions of unsaturated, polyunsaturated, and omega-3 fatty acids, and decreased saturated and omega-6 fatty acids. At 0-d storage, HVE diet did not affect thiobarbituric acid-reactive substances (TBARS) at any sampling week, and fasted fish generated fewer TBARS compared to non-fasted fish.     

熟化方式及储存条件对亚麻籽粉氧化稳定性的影响

目的 探究不同熟化方式和储存条件对亚麻籽粉氧化稳定性的影响。方法 分别采用蒸汽、烘箱、微波、高压蒸煮4种熟化方式对亚麻籽进行熟化处理,将熟化的亚麻籽粉碎后测定其氧化诱导时间。将生亚麻籽粉在不同温度、光照条件、氧气条件和容器材质下储存,分别测定亚麻籽粉和储存第0、6、12、18、24、30、36、42、48、54、60、66d的氧化诱导时间。结果 不同熟化方式中,烘箱高温熟化温度90℃,烘烤时间为30 min时的亚麻籽粉具有最长的氧化诱导时间,为37.60 h,氧化稳定性较好。储存温度的降低、避光、隔绝氧气以及陶瓷材质的储存容器均有利于保持亚麻籽粉的储存稳定性。结论 合适的熟化处理方式和储存条件可以减少氧化,增强亚麻籽粉的氧化稳定性,延长其货架期,提高亚麻籽粉的应用价值。     

即食鱼糜制品贮藏过程中的品质稳定性研究

为了确定即食鱼糜制品在贮藏过程中的品质稳定性,本文研究了120℃高温杀菌的鱼糜制品在不同温度下贮藏的品质变化。样品分为两组,分别在4℃和30℃下进行贮藏,每隔一段时间后测定其破断力、破断距离、质构、持水力、白度、扫描电镜和脂肪氧化等指标,探究鱼糜制品的品质在贮藏过程中的变化。实验发现,随着贮藏时间的延长,鱼糜制品的硬度、破断力略微上升,但是弹性、内聚性和破断距离等指标没有显著变化,持水力随着贮藏时间的增大而减少。白度值在4℃贮藏过程中略微增大,但在30℃时相对平缓。从微观结构来看,鱼糜制品的三维网络凝胶结构发生了一定的改变,纤维骨架变细且断裂成小段,4℃时的网络结构较30℃相对有序和稳定。硫代巴比妥酸值(TBA)和挥发性盐基氮(TVBN)随贮藏时间的变化都呈现上升趋势,4℃下的增长比较平缓,脂肪氧化和产品腐败程度轻微。因此,低温贮藏过程中,鱼糜制品的品质趋于稳定,能有效延长货架期。      

内外源因子对花生油氧化稳定性的影响

本文首先研究花生油中的维生素E组成,共检测出8种维生素E的同分异构体,总量为281.78μg/g,其中α-生育酚占53.7%。以此为基础,以过氧化值、p-茴香胺值、DPPH自由基清除能力为评价指标,考察内源物质（α-生育酚）及外界因素（氧气、温度）对花生油氧化稳定性的影响。结果表明:在贮藏期内,低浓度（0.01%）的α-生育酚有效延缓了花生油的初级氧化进程,但在次级氧化阶段并未表现出抗氧化效果;高浓度（0.02%）的α-生育酚反而产生了促氧化作用,需要严格控制其添加量。相较于抗氧化剂α-生育酚及BHT的添加,低温、密封、充氮处理更能有效延缓花生油的氧化进程,不失为一种方便、有效且安全的保存措施。      

益生菌冻干保护剂优化及菌粉保存稳定性研究

以嗜酸乳杆菌KLDS AD1和KLDS AD2和双歧杆菌KLDS 2.0604为研究对象,研究冻干保护剂脱脂乳、蔗糖、海藻糖、葡聚糖和Vc钠盐对各菌株冻干存活率的影响,通过单因素、正交实验筛选出优化组合,得出冻干存活率均在87.81%以上。并研究采用优化后的冻干保护剂制备的各菌粉在4℃和25℃下的保存稳定性。保存稳定性实验表明:3株益生菌菌粉在4℃和25℃下保存12个月后,菌粉的活菌数最多下降2个数量级,其活菌数均在1.0×108cfu/g以上。