Microstructure of Microcapsules Consisting of Whey Proteins and Carbohydrates

Microstructure was studied on spray-dried microcapsules with wall systems consisting of mixtures of whey protein isolate (WPI) and maltodextrins (DE 5, 10, 15) or corn syrup solids (DE 24). Structure of microcapsules was appreciably affected by type of carbohydrate and by the WPI-to-carbohydrate ratio. The extent of surface indentation was inversely related to the proportion of WPI in the wall system. Ratio of low-to-high molecular weight solutes in the wall system affected structure. At a WPI-to-carbohydrate ratio of 1:1 or higher, whey proteins improved the surface-smoothness and decrease surface indentation of maltodextrin-based microcapsules. Combinations of WPI with high-DE value carbohydrates were more effective than those with carbohydrates of low DE value in limiting surface-dents formation.     

Physicochemical properties of whey protein conjugated with starch hydrolysis products of different dextrose equivalent values

Conjugation of whey protein with maltodextrin (MD) or corn syrup solids (CSS) having dextrose equivalent (DE) values in the range 6–38 was achieved by heating solutions of 5% whey protein isolate and 5% MD or CSS, initial pH 8.2, at 90 °C for up to 24 h. Maximum conjugation, with production of limited colour and advanced Maillard products was achieved after 8 h of heating. The extent of conjugation increased with increasing DE value of the MD and CSS ingredients. Conjugation increased whey protein solubility at pH 4.5 from 9% for whey protein heated alone to 24% for whey protein heated in the presence of CSS38 at 90 °C for 8 h. Conjugation of whey proteins with MD6 or CSS38 enhanced the stability to heating of protein solutions at 85 °C for 3 min with 50 mm added NaCl.     

Changes in Electrical Energy Requirements to Operate an Ice Cream Freezer as a Function of Sweeteners and Gums

Changes in electrical energy required to operate a continuous freezer were monitored for various ice cream formulae. Ice cream formulae consisted of nine different combinations of sucrose, 36 DE corn syrup, and 42 high fructose corn syrup as well as two ratios of guar gum to locust bean gum. Within the same sweetening system, a mix high in locust bean gum tended to have a lower energy demand than mix with large amounts of guar gum. This was especially pronounced in mixes with 50% 42 high fructose corn syrup and/or 50% 36 DE corn syrup solids.     

复合壁材共轭亚油酸微胶囊的制备及表征

以乳清浓缩蛋白(WPC-80)、辛烯基琥珀酸酯化淀粉(CAPSUL)及麦芽糊精(MD,DE17)为复合壁材组分,喷雾干燥制备了共轭亚油酸(CLA)微胶囊。比较了不同壁材组分微胶囊的包埋效果、色泽变化及氧化稳定性,利用场发射扫描电镜对微胶囊的微观形貌进行了表征。结果表明,麦芽糊精(MD,DE17)分别和乳清浓缩蛋白(WPC-80)、辛烯基琥珀酸酯化淀粉(CAPSUL)复合作为壁材,可改善微胶囊的氧化稳定性。大部分微胶囊直径1～5μm,内部呈空腔状,CLA油滴(50～200 nm)包埋于囊壁中。增加复合壁材中麦芽糊精(MD,DE17)的比例,微胶囊收缩加剧。     

EPA藻油微胶囊工艺及其制备过程中脂肪酸组成的变化

为防止富含EPA和DHA(54.79%)藻油氧化,以乳清分离蛋白,HI-CAP100和麦芽糊精(DE20)为壁材,采用喷雾干燥法对其进行固体化研究,以包埋率等为指标,确定最佳壁材和工艺条件,并研究了固化过程中EPA藻油脂肪酸组成变化。结果表明,HI-CAP100、乳清分离蛋白与麦芽糊精(DE20)最佳比例为2∶2∶1,单甘脂含量1%,固形物含量40%,35MPA下均质3次,进风温度185~195℃,出风温度90~100℃,载油量30%时,包埋率高达97.03%。载油量为50%时,包埋率高达92.88%。微胶囊制备过程中EPA和DHA分别仅降低了1.021%和1.327%,说明藻油在喷雾过程中PUFA氧化不明显,包埋效果较好。     

A Computer-Assisted Method for Evaluating Ingredient Substitution in Ice Cream Formulations

Development of a computer-based system to evaluate the effect of ingredient substitution in ice cream mix on product quality and freezing requirements is described. This computer program evaluates the effect of whey powder substitution for milk solids-not-fat and three sugar systems on freezing point, viscosity, and freezing time of ice cream mix. To help to evaluate potential product quality, it is also possible to predict percent unfrozen water at different storage temperatures that might be expected for the frozen ice cream. Three sugar systems evaluated are: 100% sucrose, 70% sucrose plus 30% 36 dextrose equivalent corn syrup solids and 50% 36 dextrose equivalent corn syrup solids plus 50% 55 high-fructose corn syrup.     

玻璃化微胶囊香精的研究

本文研究碳水化合物为壁材,柠檬油香精为芯材,通过喷雾干燥实现玻璃化微胶囊包埋柠檬油香精。实验结果表明,麦芽糊精(DE9-11)、玉米糖浆(DE42)和阿拉伯胶配比为1:1.5:3.75,香精含量20%～30%时,形成的玻璃态微胶囊壁结构紧密,香精加工挥发损失少;柠檬香精微胶囊Tg为108.4℃。     

植物乳杆菌CICC 20270微胶囊的制备及其特性

以植物乳杆菌CICC 20270(Lactobacillus plantarum)及椰子油/玉米油为芯材,添加到以葡萄糖值即DE值分别为25、18糖浆为壁材的乳状液中,通过喷雾干燥法制备益生菌微胶囊,考察微胶囊的菌细胞存活率、表面结构、耐热性、储藏稳定性及在模拟胃肠液中的菌细胞存活率情况。结果表明:制得的微胶囊中植物乳杆菌存活率均在90%以上。在55℃热处理条件下,各微胶囊菌活无显著性差异(p>0.05);65℃处理1、10 min后,活菌数最低的分别是DE25/椰子油和DE18/椰子油微胶囊,存活率为75.66%、49.82%;75℃热处理1、10 min后,DE18/椰子油微胶囊中活菌数均最低,存活率分别为38.40%、15.08%。在4、25、37℃储藏条件下,玉米油微胶囊储藏性质较椰子油更为稳定,活菌数更高;而在33%、52%、75%湿度条件下,糖浆的DE值不同比油脂对益生菌的存活率影响更大,且DE25糖浆给益生菌提供了更好的保护效果。在6 h体外模拟消化中,DE25糖浆/椰子油微胶囊整个过程活菌数只下降了3.88 lg CFU/g。因此,DE25糖浆更适作为益生菌壁材;添加玉米油后使得微胶囊具有更好的耐热性;而添加椰子油更有利于提高微胶囊在模拟胃肠液中的菌活数。     

Mechanical α-relaxations and stickiness of milk solids/maltodextrin systems around glass transition

BACKGROUND: Stickiness correlates with changes in mechanical α‐relaxation properties and often results from glass transition and plasticisation of amorphous food components. In this study, milk solids with maltodextrins with different dextrose equivalents (DE9 and DE17) were analysed for glass transition (T_g), α‐relaxation (T_α) and sticky point (SPT) temperatures using differential scanning calorimetry, dynamic mechanical analysis and a sticky point test respectively. RESULTS: At the same maltodextrin contents, T_g and T_α were lower for milk solids with the higher‐DE maltodextrin. Increasing maltodextrin contents gave T_g, T_α and SPT at higher temperatures, and the magnitudes of α‐relaxations with high maltodextrin (DE9 and DE17) contents were less pronounced. CONCLUSION: Stickiness was governed by glass transition and affected by skim milk/maltodextrin composition. Stickiness was reduced with increasing maltodextrin content as a result of maltodextrin miscibility with skim milk solids, particularly lactose, which changed the relaxation behaviour above the glass transition. The mixes of milk solids with low‐DE maltodextrin may show improved dehydration characteristics and powder stability resulting from increased T_g, T_α and SPT. Copyright © 2011 Society of Chemical Industry     

A PROCESS FOR PRODUCING DEHYDRATED PUMPKIN FLAKES

Single strength pumpkin puree is difficult to drum dry due to its low solids content. It was found in this investigation that the rate of dehydration and quality of the finished product were improved by the addition of corn syrup solids and starch to the puree in amounts sufficient to raise the total solids to around 16%. The quality of pies made from flakes containing added starch and corn syrup solids was also improved over those made from unmodified single strength pumpkin puree. Best results were obtained with pumpkin flakes containing approximately 46% pumpkin solids, 38% corn syrup solids and 16% starch. Based on the average overall acceptable drying conditions and product quality, a ratio of 1 part starch to 2.5–3.0 parts corn syrup solids appeared to be in the optimum range.     

A new technique for spray drying orange juice concentrate

A new technique for spray drying concentrated orange juice using dehumidified air as drying medium and maltodextrin as drying agent was developed. A pilot-scale spray dryer was employed for the spray drying process. The modification made to the original design consisted in connecting the dryer inlet air intake to an absorption air dryer. 21 DE, 12 DE, and 6 DE maltodextrins were used as drying agents. Concentrated orange juice was spray dried at inlet air temperatures of 110, 120, 130, and 140 °C and (concentrated orange juice solids)/(maltodextrin solids) ratios of 4, 2, 1, and 0.25. Data for the residue remaining on the walls were gathered and the powders were analyzed for moisture content, bulk density, rehydration, hygroscopicity, and degree of caking. The combination of maltodextrin addition and use of dehumidified air was proved to be an effective way of reducing residue formation.Industrial relevanceOrange juice powder has many benefits and economic potentials over its liquid counterparts and provides a stable, natural, easily dosable ingredient, which generally finds usage in many foods and pharmaceutical products such as flavoring and coloring agents. However, the dehydration of orange juice is not a simple task. Thus, the objective of this study was to develop a new technique for spray drying orange juice using dehumidified air as drying medium and maltodextrin as drying agent.     

Presence of Electrostatically Adsorbed Polysaccharides Improves Spray Drying of Liposomes

Spray drying of liposomes with conventional wall materials such as maltodextrins often yields nonfunctional powders, that is, liposomes break down during drying and rehydration. Electrostatically coating the surface of liposomes with a charged polymer prior to spray drying may help solve this problem. Anionic lecithin liposomes (approximately 400 nm) were coated with lower (approximately 500 kDa, LMW‐C) or higher (approximately 900 kDa, HMW‐C) molecular weight cationic chitosan using the layer‐by‐layer depositing method. Low (DE20, LMW‐MD) or high molecular weight (DE2, HMW‐MD) maltodextrin was added as wall material to facilitate spray drying. If surfaces of liposomes (1%) were completely covered with chitosan (0.4%), no bridging or depletion flocculation would occur, and mean particle diameters would be approximately 500 nm. If maltodextrins (20%) were added to uncoated liposomes, extensive liposomal breakdown would occur making the system unsuitable for spray drying. No such aggregation or breakdown was observed when maltodextrin was added to chitosan‐coated liposomes. Size changed little or even decreased slightly depending on the molecular weight of maltodextrin added. Scanning electron microscopy images of powders containing chitosan‐coated liposomes revealed that their morphologies depended on the type of maltodextrin added. Powders prepared with LMW‐MD contained mostly spherical particles while HMW‐MD powders contained particles with concavities and dents. Upon redispersion, coated liposomes yielded back dispersions with particle size distributions similar to the original ones, except for LMW‐C coated samples that had been spray dried with HMW‐MD which yielded aggregates (approximately 30 μm). Results show that coating of liposomes with an absorbing polymer allows them to be spray dried with conventional maltodextrin wall materials. Practical Application : Liposomes have attracted considerable attention in the food and agricultural, biomedical industries for the delivery of functional components. However, maintaining their stability in aqueous dispersion represents a challenge for their commercialization. Spray drying may promise a solution to that problem. However, prior to this study spray drying of liposomes often led to the loss of structural integrity. Results of this study suggest that spray drying might be used to produce commercially feasible liposomal powders if proper combinations of adsorbing and nonadsorbing polymers are used in the liquid precursor system.     

Lactose hydrolysis in acid whey with subsequent glucose isomerisation

The disposal of whey is a problem because of its high biological oxygen demand. Of the 1.8 × 10¹⁰ kg produced annually in the USA, only about half has any food or feed application (Jelen 1983). One possible approach to acid whey utilisation is the removal of the proteins either by ultrafiltration or by thermal precipitation, hydrolysis of lactose with soluble β-galactosidase (lactase, EC 3.2.1.23) and subsequent isomerisation of the glucose to fructose by the action of immobilised glucose isomerase (EC 5.3.1.5). The resulting syrup is composed of glucose, fructose and galactose plus small amounts of unhydrolysed lactose and other oligosaccharides. The syrup was found to have a predominantly sweet and slightly salty taste. Recently sucrose has been replaced in many foods by high fructose corn syrup produced by the action of glucose isomerase on glucose syrups from corn starch hydrolysates (Bucke 1981). The whey syrup also has potential as a sucrose substitute.     

The improving effect of spray-drying encapsulation process on the bitter taste and stability of whey protein hydrolysate

Although whey protein hydrolysate (WPH) possesses good physiological functionality, its bitter taste and hygroscopic property limit its direct utilization as food ingredient. The aim of this work was to encapsulate whey protein hydrolysate by spray drying using maltodextrin or maltodextrin/??-cyclodextrin mixture as wall materials to attenuate the bitter taste and enhance the stability of whey protein hydrolysate. Hygroscopicity, glass transition temperature, bitter taste, and morphology of non-encapsulated WPH and encapsulated WPH were evaluated. Solubility, particle size, bulk density, and moisture content were also measured. Compared with the non-encapsulated WPH, the encapsulated WPH exhibited significantly lower hygroscopicity and higher glass transition temperature. The bitterness of both maltodextrin-encapsulated WPH and maltodextrin/??-cyclodextrin-encapsulated WPH was significantly lower than that of the original non-encapsulated WPH. Morphological analysis by scanning electron microscopy showed that the microcapsules of the spray-dried encapsulated WPH were matrix-type with less link bridge and had a continuous wall with many concavities. In addition, encapsulation process did not exert negative effect on the solubility of whey protein hydrolysate. The results indicated that encapsulation with maltodextrin and ??-cyclodextrin as carriers was helpful to attenuate the bitter taste and enhance the stability of whey protein hydrolysate.     

Effect of sweetener types on chemical and sensory quality of frozen kiwifruit concentrates

Fresh, mature kiwifruits, not suitable for the fresh market, were used to prepare frozen kiwifruit concentrate. Sucrose, 62 DE corn syrup and high-fructose Cornsweet₅₅ were used either alone or in various combinations on the same dry basis to prepare six sweetener types.The acidity, soluble solids, and ascorbic acid content of the fresh kiwifruit pulp and concentrates are presented. The high performance liquid chromatography method (HPLC) was used to quantitatively analyse the oligosaccharides present in the concentrates. Colour measurements made with a Hunter colour difference meter indicated that the kiwifruit concentrates differed in colour attributes, depending on the holding temperature. Objective measurements with a Brookfield viscometer indicated that the consistency of the concentrates varied with the sweetener types. The concentrate made with 62 DE corn syrup and sucrose (1:2) was thickest in consistency.Kiwifruit nectars prepared from frozen concentrates sweetened with either sucrose alone or Cornsweet₅₅ alone were preferred by the taste panel to the others.     

Oxidative Stability, Structure, and Physical Characteristics of Microcapsules Formed by Spray Drying of Fish Oil with Protein and Dextrin Wall Materials

ABSTRACT: Maltodextrins and a highly branched cyclic dextrin (HBCD) were tested for their ability to serve as wall materials for microcapsules with proteins. HBCD or a maltodextrin of DE18 with sodium caseinate (SC) improved the oxidative stability of encapsulated fish oil; however, the DE18/SC wall system had 2 disadvantages: browning induced by the Maillard reaction and agglomeration. The oil load level and the selection of dextrin strongly affected the outer topography and the inner structure, as well as the ratio of the oil to dextrin on the surface of the microcapsules. It is stated that drying speeds of dextrin and oil load levels were shown to be likely related to the structural difference in the microcapsules.     

Maillard Reaction Products as Encapsulants for Fish Oil Powders

The use of Maillard reaction products for encapsulation of fish oil was investigated. Fish oil was emulsified with heated aqueous mixtures comprising a protein source (Na caseinate, whey protein isolate, soy protein isolate, or skim milk powder) and carbohydrates (glucose, dried glucose syrup, oligosaccharide) and spray‐dried for the production of 50% oil powders. The extent of the Maillard reaction was monitored using L*, a*, b* values and absorbance at 465 nm. Encapsulation efficiency was gauged by measurement of solvent‐extractable fat and the oxidative stability of the fish oil powder, which was determined by assessment of headspace propanal after storage of powders at 35 °C for 4 wk. Increasing the heat treatment (60 °C to 100 °C for 30 to 90 min) of sodium caseinate‐glucose‐glucose syrup mixtures increased Maillard browning but did not change their encapsulation efficiency. The encapsulation efficiency of all heated sodium caseinate‐glucose‐glucose syrup mixtures was high, as indicated by the low solvent‐extractable fat in powder (<2% powder, w/w). However, increasing the severity of the heat treatment of the sodium caseinate‐glucose‐glucose syrup mixtures reduced the susceptibility of the fish oil powder to oxidation. The increased protection afforded to fish oil in powders by increasing the temperature‐time treatment of protein‐carbohydrate mixtures before emulsification and drying was observed irrespective of the protein (sodium caseinate, whey protein isolate, soy protein isolate, or skim milk powder) and carbohydrate (glucose, glucose/dried glucose syrup, or oligosaccharide/dried glucose syrup) sources used in the formulation. Maillard reaction products produced by heat treatment of aqueous protein‐carbohydrate mixtures were effective for protecting microencapsulated fish oil and other oils (evening primrose oil, milk fat) from oxidation.     

Spray drying conditions for orange juice incorporated with lactic acid bacteria

This work aimed to develop an orange juice powder by spray drying with lactic acid bacteria (Lactobacillus plantarum 299v and Pediococcus acidilactici HA‐6111‐2), testing their survival both during drying and storage (room temperature and 4 °C). Initially, the best conditions for spray drying were chosen to allow the best survival of each LAB: (i) inlet air temperature of 120 °C and (ii) 0.5:2 ratio of the orange juice soluble solids and drying agent added (prebiotics: 10 DE maltodextrin or gum Arabic). Survival of LAB was not affected by drying process, and it was higher when cultures were stored at 4 °C. A slightly higher protection was conferred by 10 DE maltodextrin, in the case of L. plantarum and at 4 °C. Pediococcus acidilactici was more resistant during storage at 4 °C, with logarithmic reductions lower than 1 log‐unit. It was demonstrated that it is possible to produce a functional nondairy product, orange juice powder supplemented with prebiotic compounds, containing viable LAB for at least 7 months, when stored at 4 °C.     

Feasibility Study for Determination of the Dextrose Equivalent (DE) of Starch Hydrolysis Products with Near‐Infrared Spectroscopy (NIRS)

Starch hydrolysis products such as maltodextrin and glucose syrup have many applications in the pharmaceutical and food industry. Several physical and functional properties, for example sweetness, compressibility and viscosity vary according to the extent of starch hydrolysis which is characterized by the dextrose equivalent (DE) value. The Pharmacopoeias use the titrimetric Lane Eynon method with alkaline Fehling's solution for determination of DE. In order to replace this empirical method, near‐infrared (NIR) calibration models for the reagent‐free determination of DE were developed. The maltodextrin model with a DE of less than 20 showed very good correlation with r = 0.97. The correlation of the extended model of maltodextrin and spray‐dried glucose syrup with a DE up to 44 was calculated to be r = 0.99. The NIR method is a very effective, rapid and non‐destructive alternative to the current pharmacopoeial procedure.