Influence of Dryer Infeed Matrices on the Retention of Volatile Flavor Compounds During Spray Drying

The retention of volatile flavor compounds (octane, 2-octanone, octanal, methyl-2-octenoate, oct-1-en-3-ol, octanol, thiophene, 2-ethylthiophene, thiazole, 2,5dimethylpyrazine, benzaldehyde, 5-methylfurfural) in model food systems during spray drying was studied. The flavor compounds were added to different model food systems (including malto dextrins DE 10 to 36.5, soy, casein and whey protein based systems and protein/fat systems) at 1 ppm and then spray dried using a Niro Utility Dryer employing centrifugal atomization. Flavor retention was found to be inversely related to DE of the maltrin carrier. Inclusion of protein in the infeed material resulted in better flavor retention than pure maltrin infeeds. Soy protein based model systems were most effective in retaining flavors followed by casein and whey protein based systems. Relative volatility of flavor compounds in different model systems was found to be an important factor pertaining to flavor retention during drying in different infeed materials.     

Effects of Blueberry (Vaccinium corymbosum) Juice on Lipid Oxidation During Spray Drying of Microencapsulated Menhaden Oil

This study investigated the effect of blueberry juice on menhaden oil lipid oxidation during microencapsulation. Oil in water emulsions containing menhaden oil with 0, 5, or 10% blueberry juice were spray dried to produce control-M, 5% BJ-M, and 10% BJ-M microencapsulated powders, respectively. All microencapsulated powders had similar encapsulation efficiencies with low surface oil content. Peroxide value (meq/kg of oil) was 4.50, 4.31, and 3.38 for control-M, 5% BJ-M and 10% BJ-M, respectively. Ten percent BJ-M had lower (P < 0.05) anisidine value, and totox values than 5% BJ-M and control-M. This indicated that 10% blueberry juice reduced lipid oxidation in menhaden oil during microencapsulation to a greater extent than the other formulations.     

Prediction of Flavor Retention during Spray Drying: An Empirical Approach

A rapid, semi-quantitative prediction model was developed for retention of volatile organic flavoring compounds during spray drying. Nonequilibrium vapor phase flux and effective (liquid phase) diffusion coefficients of lemon oil and/or butanol isomers (n-, sec-, tert-) correlated with spray dryer retention. Prediction of retention of these compounds was dependent on the specific sample matrix and dryer.     

Impact of Milk Protein Type on the Viability and Storage Stability of Microencapsulated Lactobacillus acidophilus NCIMB 701748 Using Spray Drying

Three different milk proteins — skim milk powder (SMP), sodium caseinate (SC) and whey protein concentrate (WPC) — were tested for their ability to stabilize microencapsulated L. acidophilus produced using spray drying. Maltodextrin (MD) was used as the primary wall material in all samples, milk protein as the secondary wall material (7:3 MD/milk protein ratio) and the simple sugars, d-glucose and trehalose were used as tertiary wall materials (8:2:2 MD/protein/sugar ratio) combinations of all wall materials were tested for their ability to enhance the microbial and techno-functional stability of microencapsulated powders. Of the optional secondary wall materials, WPC improved L. acidophilus viability, up to 70 % during drying; SMP enhanced stability by up to 59 % and SC up to 6 %. Lactose and whey protein content enhanced thermoprotection; this is possibly due to their ability to depress the glass transition and melting temperatures and to release antioxidants. The resultant L. acidophilus powders were stored for 90 days at 4 °C, 25 °C and 35 °C and the loss of viability calculated. The highest survival rates were obtained at 4 °C, inactivation rates for storage were dependent on the carrier wall material and the SMP/d-glucose powders had the lowest inactivation rates (0.013 day^?1) whilst the highest was observed for the control containing only MD (0.041 day^?1) and the SC-based system (0.030 day^?1). Further increase in storage temperature (25 °C and 35 °C) was accompanied by increase of the inactivation rates of L. acidophilus that followed Arrhenius kinetics. In general, SMP-based formulations exhibited the highest temperature dependency whilst WPC the lowest. d-Glucose addition improved the storage stability of the probiotic powders although it was accompanied by an increase of the residual moisture, water activity and hygroscopicity, and a reduction of the glass transition temperature in the tested systems.     

Foam Spray Drying Methods of Making Readily Dispersible Nonfat Dry Milk

A method of making a readily dispersible nonfat dry milk by injection of gas into the high-pressure feed line is described and compared with the conventional process for making an instantized powder. The foam spray drying method produces a quickly dispersible product during drying without a subsequent agglomerating step; it permits a greatly increased dryer output, since gas injection improves the efficiency of water removal and makes possible the drying of skimmilk concentrates up to 60% solids; it reduces costs of instant powder manufacture by requiring only minor equipment changes which do not affect the efficiency of the dryer to produce standard type powder. The one-step foam spray dried particle differs from the two-step agglomerated particle, in that it contains gas vacuoles in its structure which, on reliquefying, cause the particle to float before it rapidly dissolves, and more foam to form on the milk surface.     

双歧杆菌微胶囊喷雾干燥工艺的影响因素研究

选择明胶为壁材,以两歧双歧杆菌(Bifidobacterium bifidus)Bbm为实验菌株,采用喷雾干燥的方法制成徽胶囊。研究了喷雾干燥过程中的固形物浓度、进样流量、进风温度、出口温度对微胶囊产率及菌体存活率的影响,确定最佳操作工艺参数为:固形物浓度为3%,进样流量为360 mL/h,进风温度为105℃,出口温度为54～57℃,微胶囊产率为65.7%,活菌存活率为53.5%,活菌数超过1×10~(10)cfu/g。     

Spray Drying of Goat Milk Protein Hydrolysates with Angiotensin Converting Enzyme Inhibitory Activity

A goat milk hydrolysate was stabilized by spray drying using different inlet air temperatures (170–230 °C) and feed flow rates (4–12 mL/min) following a central composite experimental design. In order to evaluate the effect of operational conditions on process yield, powder properties (density, moisture, hygroscopicity, and solubility) as well as angiotensin converting enzyme (ACE) inhibitory activity, experimental data were analyzed by response surface methodology. Input variables showed a significant influence on yield, density, and moisture, while hygroscopicity, solubility, and ACE inhibitory activity were not affected. The dried hydrolysate presented an average IC₅₀ value of 273.13 μg/mL, which involved a loss of 25 % in ACE inhibitory activity with respect to the feed. The variations detected in the low molecular weight fractions of the dried hydrolysates could be responsible for the variations in ACE inhibitory activity.     

喷雾干燥及热风干燥对南瓜粉营养特性和感官品质的影响

以新鲜南瓜为原料,分别研究了喷雾干燥及热风干燥两种不同干燥工艺对南瓜粉营养特性和感官性能的影响,重点研究了喷雾干燥的干燥温度、压缩空气流量与改良剂添加量(南瓜固形物与麦芽糊精比例)及热风干燥的干燥温度,物料厚度与改良剂添加量(南瓜固形物与麦芽糊精比例)三个因素的影响,以南瓜粉成品的Vc和β-胡萝卜素含量及感官评分作为评...     

酸化及浓缩对龙眼粉加工的影响

以龙眼为原料 ,研究了加工过程中龙眼汁酸化和浓缩对龙眼喷雾干燥的影响。结果表明 :在打浆时添加龙眼果肉质量的 0 0 5 %～ 0 10 %的柠檬酸 ,将龙眼汁浓缩至固形物含量为 36 %进行喷物干燥可获得满意的结果。     

双元助留助滤体系的作用效果初步研究——PEO／PFR在含机木浆中的应用

本文探讨了不同分子量的PEO和不同的PEO／PFR配比在含机木浆的新闻纸抄造中，对抄造性能和纸页物理性能的影响。     

热风干燥加工对南极磷虾肉脂质品质的影响

研究不同热加工温度及时间对南极磷虾肉脂质品质的影响,确定最佳热风干燥加工工艺。将南极磷虾肉在不同温度和时间下进行热风干燥,冷冻干燥得到南极磷虾粉,用正己烷和无水乙醇混合溶液提取其中的油脂成分,并测定其过氧化值、酸值、硫代巴比妥酸值和脂肪酸组成。结果表明,热风干燥温度和时间对南极磷虾肉脂质品质有显著影响,加工温度升高,脂质过氧化值、酸值和TBA值升高;加工时间延长,TBA值呈现先上升后下降趋势,而酸值和过氧化值受时间影响不大;加工温度和时间对脂肪酸组成均无显著性影响。南极磷虾肉最佳热风干燥加工条件为65℃、1 h,在此条件下,磷虾肉脂质过氧化值1.02 meq/kg,酸值30.950 mg/g,TBA值0.440,多不饱和脂肪酸占比47.766%。     

造纸红液喷雾干燥研究

在3种不同的进出口气体条件下对亚硫酸镁盐法蒸煮苇浆的造纸红液进行了离心喷雾干燥实验。综合考虑产品的湿含量及成份,以进气温度250℃,出口气体85℃时所得产品质量最佳。进一步测定了干粉的干燥曲线,以验证一级喷雾干燥的合理性。另外在实验过程中发现了产品具有吸湿性,并测定了干粉的等温吸附线。图3表1参9     

Microencapsulation of Propolis in Protein Matrix Using Spray Drying for Application in Food Systems

Propolis presents several health benefits due to the presence of bioactive compounds, mainly phenolic compounds; however, its application in food is limited due to undesirable odor and low water solubility. The bioactive compounds are usually susceptible to degradation by exposure to light, heat, or oxygen or by interaction with other compounds, which may limit its biological activity. The study aimed the propolis extract microencapsulation using rice, pea, soybean, and ovoalbumin proteins as wall material by spray drying and to analyze their in vitro digestion. The propolis extract presented a high concentration of apigenin. Encapsulation efficiency was greater than 70%, and it was maintained the antioxidant activity of propolis (88% inhibition of DPPH for propolis extract and >?73% for the microparticles). The DSC, ATR-FTIR, and X-ray diffraction techniques confirmed the encapsulation. The microparticles showed different shapes, sizes, and physical characteristics. The microparticles encapsulated with pea protein could be used in formulations of Minas Frescal cheese due to the controlled released, whereas the other microparticles could be used in pudding formulations.     

Effect of Spray Drying Encapsulation of Thermotolerant Lactic Acid Bacteria on Meat Batters Properties

Four thermotolerant lactic acid bacteria (LAB) were spray dry encapsulated with Acacia gum and inoculated in cooked meat batters. Physicochemical properties (total moisture content, expressible moisture, and cooking stability), pH and acidity, CIE-Lab color, and texture profile analysis were performed at 1 and 8 days of storage at 4 °C. LAB and Enterobacteria counts were determined at 1, 4, and 8 days of storage. Control treatment was inoculated with the same unencapsulated strains as free cells. Total moisture, water activity, and fat release significantly (p?<?0.05) increased in spray drying inoculated samples, with no change in expressible moisture. No significantly (p?>?0.05) difference in pH and acidity were detected between encapsulated LAB and free cells inoculation. Inoculation of spray dry bacteria significantly (p?<?0.05) decreased samples luminosity and redness, with no change in yellowness. In TPA, hardness and springiness had no significantly (p?>?0.05) change due to inoculation type, but cohesiveness decreased in encapsulated samples. Inoculation of spray-dried LAB enhanced initial LAB count with a concomitant Enterobacteria reduction. These results suggest that the spray drying encapsulation is an effective way to protect thermotolerant lactic bacteria. These capsules can be inoculated in cooked emulsified meat products in order to ensure their survival before, during, and after processing. Thermotolerant LAB could be employed as bioprotective cultures to improve microbial safety in cooked meat products since the Enterobacteria counts were diminished during storage, enhancing the nutritional values with no major detrimental effect on textural or physicochemical properties of these kinds of foodstuffs.     

A Critical Review on the Spray Drying of Fruit Extract: Effect of Additives on Physicochemical Properties

Spray drying accomplishes drying while particles are suspended in the air and is one method in the family of suspended particle processing systems, along with fluid-bed drying, flash drying, spray granulation, spray agglomeration, spray reaction, spray cooling, and spray absorption. This drying process is unique because it involves both particle formation and drying. The present paper reviews spray drying of fruit extracts, such as acai, acerola pomace, gac, mango, orange, cactus pear, opuntia stricta fruit, watermelon, and durian, and the effects of additives on physicochemical properties such as antioxidant activity, total carotenoid content, lycopene and β-carotene content, hygroscopy, moisture content, volatile retention, stickiness, color, solubility, glass transition temperature, bulk density, rehydration, caking, appearance under electron microscopy, and X-ray powder diffraction. The literature clearly demonstrates that the effect of additives and encapsulation play a vital role in determining the physicochemical properties of fruit extract powder. The technical difficulties in spray drying of fruit extracts can be overcome by modifying the spray dryer design. It also reveals that spray drying is a novel technology for converting fruit extract into powder form.     

Mimicking Spray Drying by Drying of Single Droplets Deposited on a Flat Surface

The inactivation of bioactive ingredients during spray drying is often matrix specific. Therefore, the design of new processes or the optimisation of existing spray drying processes is usually highly product specific and requires numerous experiments. Rapid experimentation methods that facilitate fast data generation are therefore desired. A novel method for drying single droplets to mimic spray drying is proposed. The approach involves droplet deposition on a hydrophobic flat surface followed by controlled drying. A heat and mass transfer model is applied to predict the drying history of the single droplets. The approach is successfully evaluated through studying the inactivation of β-galactosidase during drying. The heat and mass transfer model supplemented with inactivation kinetics provided reasonable prediction of the residual enzyme activity after drying. In addition, the inactivation kinetics could be directly extracted from single droplet experiments rather than using the kinetics from separate heating experiments. Finally, it was demonstrated that the inactivation kinetics found with the single-drop experiments could satisfactorily predict the residual activity of β-galactosidase dried with a laboratory-scale spray dryer.     

乳粉二级干燥实验研究

乳粉干燥是耗能较大的一种操作过程，优化干燥过程具有十分重要的意义。通过实验研究二级干燥系统中振动动流化床干燥全脂淡乳粉、全脂甜乳粉及母乳化乳粉的性质，确定了合适的干燥工艺，并比较了３种乳粉振动流化干燥的不同特点。     

Kinetic History Effect on Lipid Oxidation of Methyl Linoleate in a Model System

Oxygen uptake of a model system containing methyl linoleatc (200 ppm of BHA) was conducted at 25°, 35° and 45°C. An activation energy of 20 Kcal/mole was found. Samples held for various reaction extents at 45°C were transferred to 30°C and the subsequent reaction rates was measured and compared to samples always held at 30°C. The results showed that the rate of oxidation for the samples shifted to 30°C from 45°C was significantly increased (40% to 130%). This illustrates the problem in using Arrhenius kinetic data to predict reaction extent in foods undergoing a transient temperature distribution.