R‐Index Measure of Microencapsulated Tributyrin in Gamma‐Cyclodextrin Influenced by Drying Method

Microencapsulation is commonly used in the food industry for a variety of purposes including added ingredient functionally and taste‐masking for those ingredients with negative sensory qualities. Tributyrin (TB), a source intestinally‐essential butyric acid, possesses negative aroma (cheesy, fecal) and taste (bitter) qualities. This has significantly limited its use in food applications for the potential improvement of intestinal health. Utilizing spray drying and low‐temperature oven drying, microcapsules containing TB were produced using whey (WPI), WPI and inulin, and gamma‐cyclodextrin (GCD). To determine how microcapsule formulation and drying method affected the perception of TB relative to a control, microencapsulated and free TB were added to an infant formula system and evaluated using the rating method to determine R‐index measures. Pooled R‐index measures (α = 0.01, 2‐tailed, and n = 170) indicated that the only microcapsule not significantly different from the control (R‐index below 57.95%) was the GCD and TB oven dried (GCT OD) microcapsule. All other WPI, WPI–inulin, and GCD and TB spray‐dried (GCT SD) microcapsules were all significantly different from the control. Average individual R‐index results indicated that all microcapsules in infant formula, except for GCT OD, were significantly different (P < 0.01) from the control formula but not from free TB. Spray drying may create microcapsules with surface TB and disturb the GCD–TB complex, allowing free, and surface TB to be perceived by the panelists. The GCT OD microcapsule has the potential to be used for the potential oral treatment of intestinal disorders in functional food applications without the negative sensory qualities of TB.     

In Vitro Digestion and Fermentation of Microencapsulated Tributyrin for the Delivery of Butyrate

Butyrate possesses negative sensory qualities and is most effectively utilized in the intestine to provide energy to the colonocyte for the maintenance of intestinal health. Butyrate has also shown promise in the treatment of intestinal disorders and diseases such as short bowel syndrome, inflammatory bowel disease, and colon cancer. To modify sensory properties, intestinal release, and butyrate production capabilities, tributyrin (TB) was microencapsulated in whey protein isolate (WPI)‐based and gamma‐cyclodextrin (GC)‐based materials. Using an in vitro digestion and fermentation model, microcapsules containing TB were monitored for their release and production of butyrate in vitro. All samples containing TB showed limited butyrate release (<5%) during oral and gastric stages. In the small intestinal phase, all microcapsules containing TB released approximately 75% of their total butyrate with no significant differences (P > 0.05) across formulations. During the fermentation phase, GC‐based microcapsules produced significantly more butyrate (P < 0.001) on a molar basis than all WPI‐based microcapsules. Butyrate production increased significantly (P < 0.001) over each time interval with GC‐based microcapsules having the highest during the 12 h of fermentation. The GC‐based TB encapsulation systems were able to effectively deliver butyrate to the small intestine and generate butyrate in the large intestine. These microcapsules may, therefore, be beneficial for the maintenance of intestinal health and improvement of disease states across all areas of the gastrointestinal tract.     

Tuna oil and Mentha piperita oil emulsions and microcapsules stabilised by whey protein isolate and inulin: characterisation and stability

Whey protein isolate (WPI) and its polysaccharide complexes have been widely used to prepare oil‐in‐water emulsions. The aim of this study was to evaluate the emulsions and spray‐dried microcapsules containing tuna oil and/or mint oil and stabilised by combination of WPI with inulin in terms of physicochemical characteristics and storage stability. Stable emulsions were formed before drying. Tuna oil + Mentha piperita oil emulsions had smaller viscosity, surface tension and size than did tuna oil emulsions. Surface morphology showed that spray‐dried microcapsules were spheres but had many dents and apparent shrinkage. During storage, tuna oil and tuna oil + M. piperita oil microcapsules became larger. In the blend oil microcapsules, menthone was reduced to form menthol, loss of DHA and EPA was slightly less, the degree of oxidation characterised using peroxide value and headspace propanal was less but basically greater than half of that of WTI microcapsules.     

Physical and chemical properties of encapsulated rosemary essential oil by spray drying using whey protein–inulin blends as carriers

The objective of this study was to evaluate the influence of whey protein isolate (WPI) and inulin blends on the properties of rosemary essential oil microencapsulated by spray drying. The following ratios (w/w) of WPI to inulin were evaluated: 1:1, 1:3 and 3:1. Increasing the WPI concentration increased the particle instantanisation times and decreased the moisture content. The samples did not differ significantly (P > 0.05) in hygroscopicity and porosity. The microcapsules produced at higher inulin concentration showed the highest bulk density and tapped density and were significantly different from other treatments. WPI/inulin blends of 1:1 and 3:1 proved to be effective carriers to entrap rosemary essential oil. The encapsulated oil composition in particles proved to be quite similar to pure oil, and no interaction between wall matrix and encapsulated oil was demonstrated. The analysis of particle size distribution revealed that the particle size varied from 11.5 to 11.9 μm and that all samples had an amorphous structure.     

Stability of Cardamom (Elettaria Cardamomum) Essential Oil in Microcapsules Made of Whey Protein Isolate,Guar Gum,and Carrageenan

The effects of microencapsulating cardamom essential oil (CEO) in whey protein isolate (WPI) alone and combined with guar gum (GG) and carrageen (CG) on microencapsulation efficiency, oil chemical stability, and microcapsule structure were investigated. Freeze‐dried microcapsules were prepared from emulsions containing (w/w): 15% and 30% WPI; 0.1% GG, and 0.2% CG as wall materials with CEO (at 10% of polymer concentration) as core material, and physical properties and chemical stability were compared. Bulk density of microcapsules was highest in WPI without GG or CG and in 30% WPI + GG microcapsules, and was more affected by moisture content (r = ?0.6) than by mean particle diameter (d₄₃; r = ?0.2) and span (r = 0.1). Microcapsules containing only WPI had the highest entrapped oil (7.5%) and microencapsulation efficiency (98.5%). The concentrations of 1,8‐cineole and d‐limonene were used as indicators for microcapsule chemical stability since they were the main components of CEO. Microcapsules retained higher (P ≤ 0.05) concentrations of both components than non‐microencapsulated CEO during 16 wk storage at 20 ºC, but higher loss of both components was noted at 35 ºC. Microencapsulated d‐limonene was reduced faster than 1,8‐cineole regardless of temperature. The 30% WPI and 30% WPI + GG microcapsules retained CEO best throughout storage at both storage temperatures. Scanning electron micrographs revealed that WPI microcapsules had smooth surfaces, were relatively homogenous and regular in shape, whereas GG and CG addition increased visual surface porosity and reduced shape regularity. It was concluded that the best formulation for encapsulating CEO was 30% WPI.     

Influence of inulin/oligofructose on the acid‐induced cold aggregation and gelation of preheated soy proteins

BACKGROUND: In recent years inulin‐type prebiotics have attracted much attention due to consumers' awareness of the health benefits of functional foods. Currently no information is available about the possible texture‐modifying effect of these non‐ionizable polar carbohydrates in different soy‐based food systems. In this study, the effect of inulin/oligofructose on the cold aggregation and gelation of preheated soy protein isolate (SPI) and its fractions (7S, 11S, and their mixture), induced by glucono‐δ‐lactone (GDL), were evaluated by turbidity (A₆₀₀) and dynamic rheological measurements. RESULTS: Oligofructose significantly delayed the aggregation of all protein samples and decreased the end‐point optical density of 11S fraction and SPI. Inulin, a long‐chain fructan, only delayed the aggregation of 7S globulin and reduced the capacity of aggregation (A₆₀₀) of SPI. While oligofructose showed no significant effect, the addition of 5% (w/v) inulin enhanced the gelation of SPI and the 7S/11S mixture, which was demonstrated by the increase in gel storage modulus up to 13.6% and 10.1% (P < 0.05), respectively. CONCLUSION: Inulin was found to enhance the viscoelastic properties of GDL‐induced cold‐set soy protein gels. It is expected that ‘functional’ cold‐set gel products with improved texture can be prepared from preheated soy proteins and inulin. Copyright © 2009 Society of Chemical Industry     

Wheat- and barley-based diets with or without additives influence broiler chicken performance, nutrient digestibility and intestinal microflora

BACKGROUND: To our knowledge, there is scant literature on comparative broiler response to cereal diets high in soluble non‐starch polysaccharides without or with enzyme, prebiotic, probiotic or synbiotic supplementation. In the present study, the effects of a wheat‐ and barley‐based diet with or without supplemental xylanase plus β‐glucanase, inulin, Enterococcus faecium or inulin plus Enterococcus faecium, on bird performance, digesta viscosity, nutrient digestibility and intestinal microflora were compared to a maize‐based diet. RESULTS: In comparison to a maize‐based diet, the wheat‐ and barley‐based diet reduced (P < 0.05) body weight gain and feed intake, but did not affect to the feed‐to‐gain ratio. Apparent digestibility of crude fat and various fatty acids were decreased (P < 0.05) as well as apparent metabolisable energy corrected to zero nitrogen retention content. There was an increase (P < 0.05) in the viscosity of jejunal digesta and in the caecal numbers of Escherichia coli and lactobacilli, and a decrease in the ileal numbers of E. coli and lactobacilli. Performance parameters and nutrient digestibility were not affected (P > 0.05) by dietary inclusion of the additives used, with the exception that exogenous enzyme improved (P < 0.05) the apparent digestibility of crude fat and decreased the viscosity of jejunal digesta. Enzyme and Enterococcus faecium supplementation increased intestinal lactic acid bacteria, whereas inulin addition reduced the number of E. coli (P < 0.05). Addition of inulin–Enterococcus faecium decreased E. coli and increased bifidobacteria numbers in the caeca. CONCLUSION: Enzyme supplementation to a wheat‐ and barley‐based diet significantly improved the apparent digestibility of dietary fat. All four additives had a beneficial effect on the intestinal microflora of broilers. Copyright © 2011 Society of Chemical Industry     

Chemical, Physical, and Gel-forming Properties of Oxidized Myofibrils and Whey- and Soy-protein Isolates

Myofibrils, oxidized with FeCl₃/H₂O₂/ascorbate, exhibited an increase in carbonyls and amines, SH→SS conversion, peptide scission, myosin polymerization, and a decrease in thermal stability and gel‐formation ability. Amino‐acid side chains of whey‐protein isolates (WPI) and soy‐protein isolates (SPI) were also modified during oxidation, but the thermal stability of WPI or SPI was not significantly altered. Oxidation increased elasticity of SPI gel but not that of WPI gel. Similarly, oxidation promoted interactions of myofibrils with SPI but not with WPI, resulting in > 30% increases in elasticity of the myofibril/SPI composite gel over its nonoxidized control. Hence, in processed meats where oxidation occurs, the presence of soy proteins may enhance the functionality of myofibrillar proteins.     

新型番茄红素微胶囊的制备及稳定性评价

分别以菊粉、麦芽糊精、海藻糖为壁材，以包埋番茄红素的乳清分离蛋白-壳聚糖双层乳液为芯材，使用喷雾干燥法制备番茄红素微胶囊。探究不同壁材、芯壁质量比对微胶囊包埋率、微观形貌、贮藏稳定性以及在酸性饮料模拟介质中稳定性、体外模拟释放的影响，以确定最佳新型番茄红素微胶囊的制备条件。结果表明：不同微胶囊的包埋率稳定在72.97%～81.90%之间，所有样品均呈现出典型的球状结构；随着芯壁质量比的降低，微胶囊中的番茄红素在贮藏期和酸性环境下的物化稳定性均明显增加；与菊粉相比，以麦芽糊精和海藻糖为壁材的微胶囊可实现番茄红素在模拟胃肠液中的控制释放。本研究有助于进一步开发番茄红素递送载体，从而促进其产业化应用。     

Insect‐Resistant Food Packaging Film Development Using Cinnamon Oil and Microencapsulation Technologies

Insect‐resistant films containing a microencapsulated insect‐repelling agent were developed to protect food products from the Indian meal moth (Plodia interpunctella). Cinnamon oil (CO), an insect repelling agent, was encapsulated with gum arabic, whey protein isolate (WPI)/maltodextrin (MD), or poly(vinyl alcohol) (PVA). A low‐density polyethylene (LDPE) film was coated with an ink or a polypropylene (PP) solution that incorporated the microcapsules. The encapsulation efficiency values obtained with gum arabic, WPI/MD, and PVA were 90.4%, 94.6%, and 80.7%, respectively. The films containing a microcapsule emulsion of PVA and CO or incorporating a microcapsule powder of WPI/MD and CO were the most effective (P < 0.05) at repelling moth larvae. The release rate of cinnamaldehyde, an active repellent of cinnamaldehyde, in the PP was 23 times lower when cinnamaldehyde was microencapsulated. Coating with the microcapsules did not alter the tensile properties of the films. The invasion of larvae into cookies was prevented by the insect‐repellent films, demonstrating potential for the films in insect‐resistant packaging for food products. Practical Application : The insect‐repelling effect of cinnamon oil incorporated into LDPE films was more effective with microencapsulation. The system developed in this research with LDPE film may also be extended to other food‐packaging films where the same coating platform can be used. This platform is interchangeable and easy to use for the delivery of insect‐repelling agents. The films can protect a wide variety of food products from invasion by the Indian meal moth.     

Physicochemical Characterization and Sensory Analysis of Yeast‐leavened and Sourdough Soy Breads

Sourdough fermentation has been shown to have numerous beneficial effects on bread quality, and nutritionally enhance soy‐supplemented bread by altering isoflavone chemical forms. Given this, the objective of this study was to compare the loaf quality and shelf life of sourdough and yeast‐leavened soy breads by various physical, thermal, and sensorial methods, and to assess the effects of fermentation by various microorganisms on isoflavone profile in dough and breads using high‐performance liquid chromatography analysis. Sourdough fermentation yielded a less extensible dough compared to yeast‐leavened soy dough (P < 0.001), and resulted in a harder bread crumb (P < 0.05) and lighter crust color (P < 0.001), compared to yeast‐leavened soy bread (Y‐B). Sensory analysis revealed a significantly higher overall liking of Y‐B compared to sourdough soy bread (SD‐B) (P < 0.001). Segmentation analysis of the cohort suggests that overall liking and bread consumption frequency may be determinants of Y‐B or SD‐B preference. SD‐B and Y‐B exhibited similar shelf‐life properties. Despite significantly different enthalpies associated with the melting of amylose‐lipid complexes, thermal analysis of the 2 soy breads stored for 10 d (ambient conditions) demonstrated no significant difference in water distribution and starch retrogradation (P < 0.05). Lastly, SD‐B was determined to have 32% of total isoflavones occurring in the aglycone form compared to 17% in Y‐B. These findings warrant further investigation of sourdough fermentation as a processing technique for quality and nutritional enhancement of soy‐based baked goods.     

Determination of critical storage conditions of coffee oil microcapsules by coupling water sorption isotherms and glass transition temperature

Coffee oil microcapsules were produced by spray‐drying using as encapsulating agents gum Arabic, whey protein isolate (WPI) and mixtures of maltodextrin (MD) and WPI, at three different proportions (3:1, 1:1 and 1:3). Sorption isotherms were determined by the gravimetric method, and the glass transition temperature (T_g) was measured by differential scanning calorimetry. Microcapsules produced with gum Arabic showed the highest water adsorption and underwent a stronger water plasticising effect. At the highest water activity (0.843), this sample had a T_g value of ?18.3 °C, while those produced with WPI at higher proportions showed values around 25 and 30 °C. The good fit of experimental data by Guggenheim‐Anderson‐de Boer and Gordon–Taylor models allowed the determination of the critical storage conditions, at which powders are not susceptible to deteriorative physical changes. The samples produced with 1:1 and 1:3 of MD/WPI were the most stable ones, showing critical water activity values of 0.890 and 0.938, respectively.     

Carotenoid retention and storage stability of spray-dried encapsulated paprika oleoresin using gum Arabic and Soy protein isolate as wall materials

The performance of gum arabic (GA) and soy protein isolate (SPI) on paprika oleoresin microcapsules preparation and their storage were evaluated. Paprika oleoresin emulsions with a ratio of paprika oleoresin/wall material of 1:4 (w/w) were prepared using high-pressure homogenization, and then spray dried. Both treatments showed that carotenoid retention in the microcapsules increased as inlet air temperature was increased from 160 to 200 °C, and the yellow fraction was more stable than the red fraction at all temperatures tested. Microcapsules with the highest carotenoid retention were stored at different a_w’s at 35 °C. Maximal stability for carotenoid oxidation was found at a_w’s of 0.274 and 0.710 for microcapsules prepared with GA and SPI respectively. In both treatments the lowest carotenoid degradation was associated to the minimum integral entropy zone and affected in the same way to the red and yellow pigments, during storage at 35 °C. Additionally, in contrast to microcapsules prepared with SPI, GA microcapsules were unable to retain their structural integrity at water activities above 0.743.     

不同蛋白质包埋壁材对益生菌在人体模拟胃液中的保护效果

为了提高益生菌在人体胃液中的存活率,本研究以大豆蛋白(SPI)、乳清蛋白(WPI)、酪蛋白(Casein)、明胶(Gelatin)为壁材,采用转谷氨酰胺酶交联的乳化凝胶方法,将Lactobacillus gasseri和Bifidobacterium bifidum包埋于蛋白质胶囊中,通过测定这两种益生菌在人体模拟胃液中的存活率,结果表明:相比于未经过包埋处理的细胞,包埋于蛋白质微胶囊中的细胞具有较高的存活率,并且还发现大豆蛋白微胶囊对菌的保护效果最好,明胶微胶囊最差。对于Lactobacillus gasseri,在加和未加胃蛋白酶的模拟胃液中,菌在这四种蛋白质微胶囊中的D值分别为:73.1、59.7、63.9、47.3min及246.6、240.5、220.0、90.2min。对于Bifidobacterium bifidum,在加和未加胃蛋白酶的模拟胃液中,菌在这四种蛋白质微胶囊中的D值分别为:31.7、24.2、22.7、18.7min和124.3、103.5、97.6、47.8min。除此之外,还比较了蛋白质的四种理化特性(乳化能力,凝胶强度,乳化稳定性、渗透性),其结果:乳化能力大小为SPI>Casein>WPI>Gelatin,凝胶强度大小为Gelatin>SPI>Casein>WPI,模拟胃液的渗透性大小为Gelatin>SPI=Casein>WPI,缓冲能力大小为Casein>WPI=SPI>Gelatin。通过上述结果可以推测蛋白质的缓冲能力与保护效果有很大的相关性,但缓冲能力并不是唯一决定因素,蛋白质其它的理化性质都有可能影响其保护效果。     

Prebiotic effects of fermentable carbohydrate polymers may be modulated by faecal bulking of non‐fermentable polysaccharides in the large bowel of rats

This study investigated the impact of supplementary fermentable polysaccharides inulin (a prebiotic) and barley β‐glucan on the large bowel, when consumed against a background high or low intake of mixed non‐starch polysaccharide. Rats were fed for 28 days with diets containing high (15%) and low (5%) background dietary fibre (BDF; cellulose plus sugar beet fibre), with or without 5% supplementary fermentable fibre (SFF; inulin or barley β‐glucan). High‐BDF diets unsupplemented with inulin or barley β‐glucan caused greater improvement than supplemented low‐BDF diets in several parameters linked to gut health: they increased colonic Bifidobacterium spp., butyric acid concentration in the caecum, and colonic crypt depth more than inulin and barley β‐glucan. For these parameters, inulin and barley β‐glucan added little to the effects of the high‐BDF diet alone. Furthermore, by allowing for dilution due to the greater faecal bulk induced by the mixed fibre compared with inulin or barley β‐glucan, the total quantity of butyric acid in the colon of BDF‐fed rats was greatly amplified. Interpretation of the effects of prebiotics in diets containing dietary fibre requires concurrent analysis of the multiple effects of non‐fermentable bulk.     

Encapsulation of polyphenols and anthocyanins from pomegranate (Punica granatum) by spray drying

Pomegranate (Punica granatum) bioactive compounds (polyphenols and anthocyanins) of juice (PJ) and ethanolic extracts (PE) were encapsulated with maltodextrin (MD) or soybean protein isolates (SPI) by spray drying using a 2² statistical factorial design for each systems studied (PJ–MD, PJ–SPI, PE–MD and PE–SPI) considering the proportion of coating material and the inlet temperature as independent variables. The stability of the bioactive compounds microcapsules powders obtained under optimal conditions for each system was studied at 60 °C in oven for 56 days. The polyphenols encapsulating efficiency was significantly better in SPI matrix whereas for anthocyanins was in MD matrix. By the other hand, during the storage, the MD microcapsules provided a significant greater protective effect on the polyphenols and anthocyanins than SPI, as was shown by the lower degradation rate constants. When the microcapsules were added to yogurt the stability of the bioactive compounds followed a similar behaviour to those without encapsulation, except for PE–MD.     

Stability of Trans‐Resveratrol Encapsulated in a Protein Matrix Produced Using Spray Drying to UV Light Stress and Simulated Gastro‐Intestinal Digestion

Trans‐resveratrol has demonstrated the potential to provide both therapeutic and preventive activities against chronic diseases such as heart disease and cancer. The incorporation of trans‐resveratrol into food products would allow for broader access of this bioactive compound to a larger population. However, this strategy is limited by instability of trans‐resveratrol under environmental conditions and within the digestive system leading to isomerization of trans‐resveratrol (bioactive form) to cis‐resveratrol (bio‐inactive form). Studies in the stabilization of trans‐resveratrol into protein microparticles are presented. Trans‐resveratrol was encapsulated using whey protein concentrate (WPC) or sodium caseinate (SC), with or without anhydrous milk fat (AMF). Binding of resveratrol and aromatic residues in protein was estimated utilizing the Stern–Volmer equation and the number of tryptophan residues. The stability of encapsulated resveratrol was evaluated after exposure to ultraviolet A (UVA) light and 3‐stage in vitro digestion. After UVA light exposure, SC‐based microcapsules maintained a higher trans:cis resveratrol ratio (0.63, P < 0.05) than WPC‐based microcapsules (0.43) and unencapsulated resveratrol (0.49). In addition, encapsulation of resveratrol in both protein microparticles led to an increased digestive stability and bioaccessibility in comparison to unencapsulated resveratrol (47% and 23%, respectively, P < 0.05). SC‐based microcapsules provided a higher digestive stability and bioaccessibility (86% and 81%; P < 0.05) compared to WPC‐based microcapsules (71% and 68%). The addition of AMF to the microcapsules did not significantly change the in vitro digestion values. In conclusion, SC‐based microencapsulation increased the stability of trans‐resveratrol to UVA light exposure and simulated digestion conditions. This encapsulation‐system‐approach can be extended to other labile, bioactive polyphenols.     

Effects of peptidase inhibitors and other additives on fermentation and nitrogen distribution in perennial ryegrass silage

The effects of formic acid, three concentrations of formaldehyde in a formic acid/formaldehyde mixture and cysteine‐peptidase inhibitors, 1‐trans epoxysuccinyl‐leucylamido‐(4‐guanidino) butane (E‐64), N‐ethylmaleimide and cystamine on nitrogen (N) distribution during ensilage of perennial ryegrass (Lolium perenne) were investigated. A third cut or perennial ryegrass (163 g dry matter kg⁻¹ and 61 g water‐soluble carbohydrate kg⁻¹ dry matter) was ensiled in two silo sizes; formaldehyde‐treated herbage was ensiled only in larger silos (500–550 g herbage) and cysteine‐peptidase inhibitor‐treated herbage only in smaller silos (130–150 g herbage). Control silages were poorly fermented but contained low concentrations of butyric acid and ammonia N indicating little activity of spoilage bacteria. Formic acid increased peptide N concentrations (P<0.01) in silage from smaller silos but had little effect on other N constituents; in the larger silos, formic acid reduced soluble non protein nitrogen (NPN) and ammonia‐N concentrations and increased peptide N concentrations. Increments in formaldehyde reduced silage soluble and ammonia N concentrations (linear effect; P<0.001). N‐Ethylmaleimide and E‐64 reduced soluble NPN concentrations (P<0.05) but had little effect on other N constituents. Cystamine, however, increased silage peptide N concentrations. Gel filtration on Sephadex G‐25 of silage juice prepared from control and formic acid‐treated silages suggested that most silage peptides were small, with molecular weights of less than 520 Da. © 1999 Society of Chemical Industry