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1.
Food Chem ; 302: 125332, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31404871

RESUMO

Wheat bran (WB) was treated using xylanase and arabinofuranosidase from Thermotoga maritima and added to steamed breads on 15% flour weight basis. The antioxidant capacity and water and oil retention capacity of brans were increased while their soluble xylooligosaccharides and phenolic acids content were increased. Two enzymes treatment was found to be more effective in decreasing the resistance to extension, softening degree, water absorption and development time, and in increasing the extensibility, stability time, porosity and sensorial characteristics of the steamed breads. Two enzymes treatment had significantly (P < 0.05) greater specific volume, springiness and cohesiveness and lower crumb firmness, gumminess, chewiness than single enzyme treatment. All results highlighted that combination of xylanase and arabinofuranosidase can improve the degrees hydrolysis of WB and its soluble AX xylooligosaccharides produced, having a synergetic effect on the dough rheology and nutritional and quality characteristics of steamed bread.


Assuntos
Pão , Fibras na Dieta , Endo-1,4-beta-Xilanases/química , Glicosídeo Hidrolases/química , Antioxidantes/análise , Antioxidantes/química , Fibras na Dieta/análise , Farinha , Qualidade dos Alimentos , Humanos , Hidrólise , Valor Nutritivo , Reologia , Vapor , Paladar , Triticum
2.
Food Chem ; 302: 125141, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31416000

RESUMO

Four jams were made using two wild species of Physalis spp., two containing seeds (P1WS and P2WS) and two without seeds (P1WHS and P2WHS). Physicochemical, nutraceutical and rheological properties of the jams were determined and a sensory evaluation made. P1WS and P2WS jams had lower carbohydrates contents, reducing sugars and calories, and higher fiber contents than P1WHS and P2WHS. The presence of seeds in the jams increased phenols and flavonoids. However, the seedless jams had better sensory acceptance. The dynamic rheological testing indicated a gel-like behavior (G'>G'') in whole jams. Also, shearing flow testing showed shear-thinning and thixotropic behaviors, which are shared characteristics with others fruit jams, such as mango or gabiroba. The presence of seeds in the jam affected directly yield stress, apparent viscosity, hysteresis area, and viscoelastic parameters, which were described in the sensory analysis as a "less desirable texture". The use of seeds from wild species of Physalis spp., increased the nutritional value of jam. However, it would be necessary to improve consumer acceptance through technological processes prior to marketing.


Assuntos
Suplementos Nutricionais/análise , Manipulação de Alimentos , Frutas/química , Physalis/química , Reologia , Sementes/química , Paladar , Fibras na Dieta/análise , Flavonoides/análise , Valor Nutritivo , Fenóis/análise , Viscosidade
3.
J Sci Food Agric ; 99(15): 6796-6805, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31368528

RESUMO

BACKGROUND: There are excellent opportunities for greater incorporation into our diets of pulses, which are rich in proteins and dietary fibers, if their functional properties are modified to fit a wide range of applications in the food industry. The objective of this research was to produce high protein and fiber extrudates from yellow pea and red lentil flours using conventional and N2 gas injection assisted extrusion cooking methods. The effects of process variables on extrudate functional and thermal properties were also investigated. RESULTS: The cold viscosity of extrudates produced by N2 gas injection were higher than those produced by conventional extrusion, indicating that gas-assisted extrusion does affect the end-product pasting properties. At higher barrel temperatures (150-175 °C) extrudates did not exhibit any thermal transition in their thermograms, and thus their starches were completely gelatinized and proteins completely denatured during extrusion. In general, water solubility of extrudates produced by N2 gas injection was significantly (P < 0.05) higher than those produced by conventional extrusion. Emulsion capacity and stability of yellow pea extrudates were in the range of 44-50% and 42-47%, respectively, and the counterpart values of red lentil extrudates were very similar (in the range of 43-47% and 43-46%, respectively). CONCLUSION: Nitrogen gas injection assisted extrusion cooking can be used practically in development of pulse extrudates which contain high protein and dietary fiber. This novel and innovative technique is a reliable alternative method to the conventional CO2 gas injection assisted extrusion cooking methods in the snack food and food ingredient industries. © 2019 Society of Chemical Industry.


Assuntos
Culinária/métodos , Lens (Planta)/química , Ervilhas/química , Culinária/instrumentação , Fibras na Dieta/análise , Farinha/análise , Temperatura Alta , Lathyrus , Nitrogênio/química , Viscosidade
4.
Food Chem ; 301: 125304, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31394335

RESUMO

Black rice is a variety of pigmented rice. It contains numerous nutritional and bioactive components, including essential amino acids, functional lipids, dietary fibre, vitamins, minerals, anthocyanins, phenolic compounds, γ-oryzanols, tocopherols, tocotrienols, phytosterols and phytic acid. There have been several studies of black rice due to its alleged beneficial health effects when consumed regularly. This review focuses on the historical aspects, chemical composition, and nutritional and functional properties of black rice. Furthermore, a discussion of the development of new foods and beverages with applications and processing technologies designed to improve their quality attributes. The nutritional value of black rice means that it has the potential to be used in the production of healthy foods and beverages, such as functional products and gluten-free cereals, thereby providing extra health benefits to consumers.


Assuntos
Indústria de Processamento de Alimentos/métodos , Valor Nutritivo , Oryza/química , Oryza/fisiologia , Antocianinas/análise , Fibras na Dieta/análise , Minerais/análise , Fenóis/análise , Tocoferóis/análise , Tocotrienóis/análise
5.
Food Chem ; 300: 125192, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31362158

RESUMO

Dietary fiber has several benefits for humans, and the development of healthier rice with an improved dietary fiber composition has attracted increasing amounts of attention. Based on the method of AOAC 2002.02, we developed a simplified method to screen polished rice containing high total dietary fiber (TDF). Mutant cw with a high TDF content could be distinguished easily from R7954 (indica) and Nipponbare (japonica) by the digestion-resistant phenotype, which is characterized as an almost intact grain after hydrolysis by pepsin, pancreatic α-amylase and amyloglucosidase. The individuals identified from the F2 population showed digestion resistance all had TDF content higher than 5%, while those without a digestion-resistant phenotype had TDF content lower than 5%. The phenotype of digestion resistance could be a valuable index for identifying rice with higher TDF content, and the identification of this phenotype provides a simplified, economical and high throughput method for high TDF rice breeding.


Assuntos
Fibras na Dieta/análise , Análise de Alimentos/métodos , Ensaios de Triagem em Larga Escala/métodos , Oryza/química , Culinária , Fibras na Dieta/metabolismo , Digestão , Glucana 1,4-alfa-Glucosidase/química , Glucana 1,4-alfa-Glucosidase/metabolismo , Humanos , Hidrólise , Pepsina A/química , Pepsina A/metabolismo , Sementes/química , Amido/análise , Amido/química , alfa-Amilases/química , alfa-Amilases/metabolismo
6.
Food Chem ; 298: 125085, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260951

RESUMO

Plantain is a climacteric fruit having economic relevance in several tropical regions. Unripe plantain is an alternative source of indigestible carbohydrates (dietary fibre) and undigestible starch fraction. Unripe plantain flour was explored in this work as an alternative ingredient (whole and pulp) in spaghetti formulations. Chemical composition, cooking quality, texture analysis, and microstructure of spaghetti formulations were analyzed. The microstructure results showed that the presence of fiber in the food matrix helped the reduction of the starch granule swelling in the cooking process. Spaghetti made with whole plantain flour exhibited lower rapidly starch fraction, with increased resistant starch fractions. Overall, the whole unripe plantain flour exhibited good potential for gluten-free spaghetti having highest content of fiber and lower starch digestion rates.


Assuntos
Farinha , Plantago/química , Culinária , Dieta Livre de Glúten , Fibras na Dieta/análise , Digestão , Farinha/análise , Análise de Alimentos , Amido/química
7.
Plant Foods Hum Nutr ; 74(3): 391-398, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31256321

RESUMO

A maize milling by-product was defatted by aqueous extraction and the residue was dehydrated, comminuted and sieved to obtain two powders differing in particle size and having a very high fibre content. The powders were then incorporated into the structure of short-dough biscuit, at two wheat flour substitution levels (10 and 20%), aiming at the development of a nutritionally improved product. Their impact on biscuit dough properties and the quality and sensory characteristics of the final products was evaluated. As it was revealed, powders' addition altered dough consistency and alveograph indices mainly due to interactions between wheat flour proteins and polysaccharides and enhanced the nutritional profile of the biscuits by inducing a 4- to 6-fold increase of their fibre content. Additionally, it influenced only to a limited extent the degree of some of the final product characteristics, e.g., protein and fat content, spread ratio, breaking strength, depending both on the level of incorporation and the particle size of the residue. On the whole, products' sensory quality was not negatively influenced, suggesting that it is possible to use both powders for the fortification with fibre of biscuits and possibly other bakery products.


Assuntos
Fibras na Dieta/análise , Alimentos Fortificados , Triticum/química , Zea mays/química , Pão/análise , Farinha/análise , Pós , Paladar , Água/química
8.
Food Chem ; 298: 125032, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260968

RESUMO

A dietary fibre prepared from sugarcane stalk was compared with psyllium husk and wheat dextrin. In contrast to the other dietary fibres, sugarcane fibre was found to contain significant amounts of insoluble dietary fibre (73-86%), lignin (18.66-20.23%), and rare minerals such as chromium (0.67-2.54 mg/100 g) and manganese (1.07-2.34 mg/100 g). Analysis of the ethanol extract also detected compounds with antioxidant activity. Characterisation of five sugarcane fibres prepared from selected strains, harvest periods (growth or storage phase), and processing conditions showed these factors influenced the final composition. Furthermore, using in vitro digestion, we found that potassium, magnesium, chromium, and zinc in were bioaccessible in sugarcane samples. Also, sodium was shown to bind to the sugarcane fibre potentially indicating bile salt binding activity. Results from this study support the use of sugarcane as a source of dietary fibre in functional foods.


Assuntos
Dextrinas/química , Fibras na Dieta/análise , Plantago/química , Saccharum/química , Triticum/química , Antioxidantes/análise , Cromo/análise , Cromo/farmacocinética , Dextrinas/análise , Fibras na Dieta/metabolismo , Indústria de Processamento de Alimentos/métodos , Lignina/análise , Metais/análise , Metais/farmacocinética
9.
J Agric Food Chem ; 67(30): 8419-8424, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31267740

RESUMO

Increasing the dietary fiber of staple foods such as bread is an attractive way to promote healthy eating in a large part of the population, where dietary fiber consumption is reportedly below the recommended values. However, many consumers prefer white breads, which are typically low in dietary fiber. In this work, white bread was made from two wheat cultivars with differing fiber contents. The resulting breads showed similar quality parameters (volume, specific volume, firmness, inner structure characteristics) with any differences maintained below 7%. Bread digestibility was evaluated using a novel dynamic in vitro digestion model. Reduced digestion rates of 30% were estimated for the high-fiber white bread compared to that in the control. Overall, this work demonstrates the potential to produce healthy, high-fiber white breads that are acceptable to consumers, with a reduced rate of starch digestion, by exploiting a genetic variation in the dietary fiber content of wheat cultivars.


Assuntos
Fibras na Dieta/metabolismo , Triticum/metabolismo , Pão/análise , Fibras na Dieta/análise , Digestão , Farinha/análise , Humanos , Cinética , Amido/química , Amido/metabolismo , Triticum/química
10.
J Food Sci ; 84(8): 2128-2138, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31313294

RESUMO

Fiber-enriched white sauces with apple (AF401), potato (KF200), and microcrystalline cellulose (MCC) were selected among six white sauces, all of them elaborated by replacing corn starch and milk with 3% of different dietary fibers. It was investigated the freezing/thawing (F/T) stability of these three enriched white sauces studying their physico-chemical (color, syneresis percentage, total soluble solids content), rheological (viscoelastic and steady measurements), and sensorial properties before and after a freezing/thawing treatment. White sauce with MCC resulted in being the most like the control (without fiber) showing a higher elasticity and a heat stability. Moreover, the sauce elaborated with MCC has a sensorial profile as a traditional corn starch sauce with high "creaminess" and lower "heterogeneity" after the F/T treatment. Therefore, the properties provided by MCC make this product interesting in food design, and MCC sauce could be used as an industrial frozen fiber-enriched white sauce. PRACTICAL APPLICATION: These days, there is an increase in the demand of precooked frozen dishes due to current lifestyles and because the use of fiber exhibits many proven health benefits. A béchamel sauce made from corn starch and enriched with different fibers was elaborated, frozen and thawed in microwave. Both fresh and frozen/thawed microcrystalline cellulose (MCC) sauces exhibited very similar rheological and sensorial properties to an industrial and traditional frozen white sauce without fiber. Therefore, MCC-enriched white sauce resulted to be a feasible strategy to produce a white sauce suitable for frozen dishes with good functional properties and sensorial quality.


Assuntos
Fibras na Dieta/análise , Extratos Vegetais/química , Amido/química , Zea mays/química , Celulose/análise , Farinha/análise , Manipulação de Alimentos , Congelamento , Reologia , Solanum tuberosum/química
11.
Food Chem ; 299: 125115, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31288161

RESUMO

The nutritional and antinutritional components of minor millets were correlated with mixolab dough mixing behavior and in vitro protein and starch digestibility. Total arabinoxylan (r = -0.53, p < 0.05) and dietary fiber (r = -0.66, p < 0.05) content significantly (p < 0.05) increased protein weakening. Peak viscosity negatively correlated with phenolic (r = -0.55, p < 0.05) content. The dietary fiber and phenolics suppressed retrogradation. Protein digestibility negatively correlated with tannin (r = -0.70, p < 0.05), phytic acid (r = -0.69, p < 0.05), phenolics (r = -0.79, p < 0.05), flavonoids (r = -0.72, p < 0.05) and total dietary fiber content (r = -0.84, p < 0.05). A positive correlation of resistant starch (RS) with total dietary fiber (r = 0.85, p < 0.05), phenolics (r = 0.89, p < 0.05), flavonoids (r = 0.83, p < 0.05), phytic acid (r = 0.43, p < 0.05) and tannin content (r = 0.79, p < 0.05) was observed. Millets predicted lower glycemic index than wheat and it was found to be negatively associated with the RS (r = -0.96, p < 0.05) and total dietary fiber content (r = -0.89, p < 0.05) and positively correlated (r = 0.98, p < 0.05) with rapidly digestible starch. The millets may be diversified for personalized nutrition and development of functional food.


Assuntos
Pão , Milhetes , Proteínas de Vegetais Comestíveis/farmacocinética , Amido/farmacocinética , Fibras na Dieta/análise , Digestão , Índice Glicêmico , Milhetes/química , Panicum/química , Fenóis/análise , Fenóis/química , Reologia , Setaria (Planta)/química , Amido/química , Triticum/química , Viscosidade , Xilanos/análise
12.
Food Chem ; 299: 125117, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31288164

RESUMO

This work evaluated nutritional and organoleptic properties of murta, a Chilean native berry, impregnated with Lactobacillus casei var. rhamnosus and dehydrated by different methods: freeze- (FD), convective- (CD) and vacuum- (VD) drying. Scanning electron microscopy revealed that L. casei localized at the peduncle and near the peduncle of the impregnated fruit. Murta enriched with probiotics contained higher L. casei viable counts after dehydration with FD compared to CD and VD methods. Overall, drying resulted in a decrease in crude fibre and phenolic compounds, which was attributed to L. casei metabolic activity suggesting that murta berries could act as prebiotics for L. casei. Among drying methods, L. casei enriched FD murta presented less alterations in the microstructure, less drying-induced damage and obtained a higher sensory acceptability score than CD and VD murta. Taken together, these results will contribute to the development of functional foods from regional products improving local economy.


Assuntos
Frutas/química , Lactobacillus rhamnosus , Myrtaceae/química , Chile , Dessecação , Fibras na Dieta/análise , Liofilização , Frutas/microbiologia , Humanos , Lactobacillus rhamnosus/crescimento & desenvolvimento , Myrtaceae/microbiologia , Fenóis/análise , Prebióticos , Probióticos , Sensação , Vácuo
13.
Food Chem ; 299: 125095, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31279124

RESUMO

Hydrogen gas (H2), a multifunctional signaling molecule, has received increasing attention in recent years. In the present study, hydrogen-rich water (HRW) (2 ppm) was used for the processing of sprouted black barley (Hordeum distichum L.), and the results showed that the HRW treatment could significantly increase the germination rate and growth rate of black barley (P < 0.05). A chemical component analysis showed that in sprouted black barley, the HRW treatment could change the distribution of phytochemicals (e.g., the ionic strength of guanosine), increase the concentrations of free vanillic acid, coumaric acid, sinapic acid, conjugated sinapic acid, Ca and Fe and the hydroxyl radical scavenging rate, and decrease the protein, fat, starch and dietary fibre contents compared with the results obtained after treatment with ultra-pure water (P < 0.05). HRW can be used for the processing of sprouted grains to effectively increase their germination efficiency and concentrations of bioactive phytochemicals.


Assuntos
Hordeum/química , Hordeum/crescimento & desenvolvimento , Hidrogênio/farmacologia , Antioxidantes/análise , Cromatografia Líquida , Fibras na Dieta/análise , Germinação/efeitos dos fármacos , Hordeum/efeitos dos fármacos , Radical Hidroxila/análise , Espectrometria de Massas , Proteínas de Vegetais Comestíveis/análise , Amido/análise , Água/química , Água/farmacologia
14.
Food Chem ; 299: 125092, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31280001

RESUMO

The health-promoting functions of fruit phenolic compounds are mainly attributed to their metabolites. The organic cultivation of fruits is becoming increasingly popular. Thus, this study evaluates whether the differences in red Grenache grapes derived from organic culture conditions influence the bioavailability and metabolism of phenolic compounds in rats. Organic and nonorganic (conventional) red Grenache grapes (OG and CG, respectively) were characterized and administered to Wistar rats (65 mg gallic acid equivalents/kg bw). Serum was recollected at different time points, and the phenolic metabolites were quantified by HPLC-ESI-MS/MS. The results showed that organic cultivation increased the oligomeric proanthocyanidin and anthocyanidin contents and decreased the content of free flavanols and dietary fiber. The serum profile of OG-administered rats showed higher metabolite concentrations at 2 h and reduced metabolite concentration at 24 h compared with the CG-administered rats. Thus, this particular serum kinetic behavior might influence the bioactivity of their phenolic compounds.


Assuntos
Agricultura Orgânica , Fenóis/farmacocinética , Vitis/química , Animais , Antocianinas/análise , Antocianinas/farmacocinética , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Fibras na Dieta/análise , Análise de Alimentos/métodos , Frutas/química , Masculino , Fenóis/análise , Polifenóis/análise , Polifenóis/farmacocinética , Proantocianidinas/análise , Proantocianidinas/farmacocinética , Ratos Wistar , Espectrometria de Massas em Tandem
15.
Plant Foods Hum Nutr ; 74(3): 436-442, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31321622

RESUMO

In this work, the profiles of phenolics, fiber, pectins, sugars, organic acids and carotenoids, vitamin C, ash, protein and fat contents, as well as antioxidant capacity were compared in fruits, flowers, and bark of Viburnum opulus (VO). Antioxidant capacity was evaluated against ABTS, hydroxyl, peroxyl and superoxide free radicals, and as a reducing power by using in vitro test. The results showed great quantitative differences in the composition of the VO morphological parts tested. Fruits contained the highest concentrations of fat, organic acids, sugars, soluble dietary fiber (10.57 ± 0.54; 7.34 ± 0.06; 32.27 ± 1.25; 6.82 ± 0.38 g/100 g DW, respectively) and carotenoids (2.70 ± 0.07 mg/100 g DW). Whereas, the bark exceeded the remaining parts of the VO in terms of antioxidant capacity, ash (9.32 ± 0.17 g/100 g DW), total (59.34 ± 0.75 g/100 g DW) and insoluble dietary fiber (58.20 ± 0.73 g/100 g DW) contents as well as phenolic compounds (3.98 ± 0.04 g/100 g DW). Among the phenolic compounds quantified in this study, chlorogenic acid and (+)-catechin had the highest concentrations (> 1 g/100 g DW) in the flowers and bark, respectively.


Assuntos
Antioxidantes/análise , Carotenoides/análise , Nutrientes/análise , Fenóis/análise , Viburnum/química , Ácidos Carboxílicos/análise , Catequina/análise , Ácido Clorogênico/análise , Fibras na Dieta/análise , Flores/química , Frutas/química , Especificidade de Órgãos , Pectinas/análise , Casca de Planta/química , Açúcares/análise
16.
J Dairy Sci ; 102(9): 7917-7926, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31255275

RESUMO

The objective of this study was to evaluate nutrient intake and digestibility, and growth performance of calves when fed a milk replacer (MR) at 2 feeding rates. Male Holstein calves [n = 49; 45.0 ± 5.2 (mean ± SD) kg of body weight (BW); 3 to 4 d of age] were randomly assigned to 1 of 2 MR [27% crude protein (CP), 18% fat, dry matter (DM) basis; 14% solid] feeding programs: (1) 0.66 kg of DM/d for first 39 d divided into 2 equal a.m. and p.m. meals followed by one-half of the allotment per day for 3 d fed in the a.m. feeding only (moderate); (2) 0.96 kg of DM/d for the first 42 d divided into 2 equal a.m. and p.m. meals followed by one-half of the allotment per day for 7 d fed in the a.m. feeding only (high). A textured starter fed to calves contained whole grains with 20% CP and 44% starch (DM basis). At d 56, calves were moved into groups by treatment (4 calves/pen) and fed the same starter blended with 5% hay until d 112. Data were analyzed as a completely randomized design, or as a completely randomized design with repeated measures when applicable. Over the entire nursery period (d 0-56), there were no differences in average daily gain (0.63 vs. 0.64 kg/d) and hip width change (4.44 vs. 4.57 cm) for moderate- versus high-fed calves. Apparent digestibility of DM (76.5 vs. 70.3%), organic matter (77.4 vs. 71.2%), CP (78.8 vs. 72.6%), and neutral detergent fiber (37.2 vs. 22.7%) differed between moderate- and high-fed calves when estimated at d 51 to 55. From d 56 to 112, average daily gain (0.99 vs. 0.91 kg/d), hip width change (5.32 vs. 4.68 cm), and gain/DM intake (0.335 vs. 0.307 kg/kg) were greater, but DM intake per kg of BW (0.028 vs. 0.028 kg/kg) did not differ for calves previously fed moderate versus high. Feeding calves more than 0.66 kg of DM/d from a 27% CP, 18% fat MR did not improve BW gain and structural growth in the nursery period (d 0-56), and decreased these in the grower period (d 56-112) partially through reduction in digestibility of the starter.


Assuntos
Bovinos/fisiologia , Fibras na Dieta/análise , Ingestão de Energia , Substitutos do Leite/metabolismo , Nutrientes/metabolismo , Animais , Peso Corporal , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Digestão , Masculino , Amido/administração & dosagem , Desmame , Ganho de Peso , Grãos Integrais
17.
J Appl Microbiol ; 127(4): 985-995, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31287933

RESUMO

AIMS: Ferulic acid esterase (FAE)-producing Lactobacillus species isolated from ensiled Elymus nutans growing on the Qinghai-Tibetan plateau were characterized, and effects of their application to the alfalfa ensiling process and the evidence to synergic effect between cellulase and FAE were investigated. METHODS AND RESULTS: The results of 16S rRNA gene sequence and species-specific polymerase chain reaction amplification showed that two screened strains with high FAE activity were Lactobacillus plantarum A1 (LP) and L. brevis A3 (LBr). The optimum temperature and pH for the LP and LBr was 37°C and 6·4 respectively. The FAE exhibited a good stability at temperatures between 25 and 50°C and at pH values of 5·0-7·0. The two strains and a commercial cellulase (CE) were applied as additives to alfalfa silage. After 60 days of ensiling, the lactic acid in the control and CE groups were significantly lower than those of the other treatment groups. The neutral detergent fibre and acid detergent fibre contents in the LP group were significantly lower than those observed in the other groups. At the same time, the combination of CE and FAE-producing lactic acid bacteria synergistically improved the fermentation quality of the silage. CONCLUSIONS: The addition of the FAE-producing strain of L. plantarum A1 to alfalfa silage improved its fermentation quality, and reduced the fibre content of the silage. SIGNIFICANCE AND IMPACT OF THE STUDY: The screened homo-fermentative and FAE-producing strain of L. plantarum A1 could be a candidate strain in improving fermentation quality and fibre digestibility of ensiled forages.


Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Elymus/microbiologia , Lactobacillus/metabolismo , Medicago sativa , Silagem/microbiologia , Celulase/metabolismo , Fibras na Dieta/análise , Fermentação , Ácido Láctico/análise , Ácido Láctico/metabolismo , Lactobacillus/enzimologia , Lactobacillus/genética , Medicago sativa/química , Medicago sativa/microbiologia , RNA Ribossômico 16S/genética , Silagem/análise
19.
J Food Sci ; 84(7): 1730-1736, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31218701

RESUMO

With high phytochemical and starch contents, purple-fleshed sweetpotatoes (PFSP) have been processed into various functional ingredients and food products including juices and natural colorants. For juice processing, PFSP are usually subjected to heat treatment for inactivation of pigment-degrading enzymes. However, heating of sweetpotatoes gelatinizes starch and produces thick slurry with cooked flavor, which are the drawbacks. Development of alternative processes to overcome the stated problems will be beneficial to sweetpotato processors. This study demonstrated that acidified water (≥3% w/v citric acid) was effective in inhibiting polyphenol oxidase and peroxidase in raw PFSP resulting in an attractive reddish juice. About 93% total phenolics (TP) and 83% total monomeric anthocyanins (TMA) in PFSP were extracted by two repeated extractions. The combined PFSP juice (3.2 L/kg PFSP) had high levels of TP (1,850 mg/L) and TMA (475 mg/L). With the developed process, 167 g dried starch, and 140 g dried high-fiber pomace were obtained for each kg raw PFSP, besides the highly pigmented juice. Pasteurization of the PFSP juice samples (pH 3.2) at 80 °C for 12 s resulted in 15% loss in TMA and had no effect on TP. The results indicated an efficient process to produce sweetpotato juice with high bioactive compounds and recovery of starch and high dietary fiber pomace as co-products. PRACTICAL APPLICATION: Purple-fleshed sweetpotatoes (PFSP) are rich in polyphenolics and antioxidant activities. In PFSP juice extraction, heat treatment to inactivate the pigment-degrading enzymes results in starch gelatinization and cooked flavor. A nonthermal process using acidified water was developed for producing anthocyanin-rich juice from PFSP and concurrently recovering native starch and dried pomace, which would increase the economic feasibility of the developed process. The results demonstrate an efficient process for the sweetpotato industry in producing PFSP pigmented juice and co-products for various food applications.


Assuntos
Ácidos/química , Antocianinas/análise , Catecol Oxidase/antagonistas & inibidores , Sucos de Frutas e Vegetais/análise , Ipomoea batatas/química , Peroxidase/antagonistas & inibidores , Extratos Vegetais/análise , Proteínas de Plantas/antagonistas & inibidores , Antocianinas/isolamento & purificação , Catecol Oxidase/análise , Cor , Culinária , Fibras na Dieta/análise , Ipomoea batatas/enzimologia , Peroxidase/análise , Fenóis/análise , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Proteínas de Plantas/análise , Amido/análise
20.
Food Chem ; 297: 124983, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253271

RESUMO

To improve the industrial application of wheat bran insoluble dietary fiber (W-IDF), three modification methods (carboxymethylation, complex enzymatic hydrolysis, and ultrafine comminution) were compared on the basis of structural, physicochemical, functional, and antioxidant properties of W-IDF. FT-IR, DSC and SEM analysis showed that modifications contributed to alteration in morphology and arrangement of chemical bonds in W-IDF. Carboxymethylation effectively improved the water retention (WRC), water swelling (WSC), and glucose adsorption capacities (GAC); complex enzymatic hydrolysis greatly improved the oil retention (ORC), GAC, and nitrite ion adsorption capacities (NIAC). Although ultrafine comminution reduced the WRC and ORC, while positively influenced the GAC and NIAC. Moreover, total phenol content, total antioxidant capacity, DPPH radical scavenging capacity, Fe2+ chelating capacity and total reducing power were improved in modified W-IDF. Our results confirmed that carboxymethylation can improve the nutritive quality and sensory properties of W-IDF (nutritive ingredient) in food products.


Assuntos
Antioxidantes/análise , Fibras na Dieta/análise , Complexos Multienzimáticos/metabolismo , Triticum/química , Adsorção , Antioxidantes/metabolismo , Fenômenos Químicos , Fibras na Dieta/metabolismo , Glucose/metabolismo , Hidrólise , Metilação , Valor Nutritivo , Silicones
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