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1.
Foods ; 12(16)2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37628003

RESUMEN

Okara, the solid byproduct of soymilk production, poses a sustainability concern, despite being rich in fiber and other healthful compounds. In this study, the physical properties of tofu made from soymilk fortified with differing levels of okara-either whole or fine (<180 µm)-and made with the traditional coagulant nigari were examined. The yield increased linearly with the okara concentration with values of 18.2-29.5% compared to 14.5% for the control. The initial moisture in the fortified samples was higher than the control (79.69-82.78% versus 76.78%), and both the expressible moisture and total moisture after compression were also greater in the fortified samples. With a few exceptions, the texture parameters did not differ between samples. Dynamic rheology showed that all samples had G' > G″. The storage moduli increased at different rates during each gelling step, with G' before and after gelling increasing with the fortification level, and was greater for the samples with fine particles than with whole particles. Consumer sensory panels using the hedonic scale showed traditional tofu had a slightly higher acceptability, but the panelists indicated they would be more willing to purchase okara-fortified tofu because of the health and sustainability benefits it might have. Thus, tofu could be produced with added okara with predictable but not profound changes in its physical properties.

2.
J Texture Stud ; 54(1): 115-126, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36146907

RESUMEN

The studies expounding on the effects of storage conditions on texture changes are limited. The researchers have been proposing methods to measure pecan texture instrumentally. But current protocols and/or attributes fail to address huge variability during experimentation. Additionally, there are no predictive models to estimate changes in pecan texture during storage. This study addresses all the above concerns and investigates the effects of different relative humidity (RH, 30-90%) and packaging material (Polyethylene-Nylon [PEN], polypropylene [PP], low density polyethylene [LDPE], and metallic laminates [ML]) on pecan texture, introducing a rift ratio (F/H or fracturability to hardness ratio) to address variability in the data and predictive model to estimate changes in the textural attribute of pecans during storage. The textural analysis was conducted on pecan cores and intact pecans to measure the area under curve, fracturability, hardness, cohesiveness, chewiness, springiness, and rift ratio. It was observed that values for the rift ratio obtained using the intact pecan method had high R2 (0.72) as compared to the rest of the textural attributes. A three-parameter logistic model was employed to predict pecan texture during storage. The pecans stored at 75, 80, and 90% reached the rift ratio (F/H) of 0.5 at approx. 115, 3, and 0.15 days (~ 4 hr), respectively. Similarly, pecans stored in LDPE, PP, and PEN packs at 80% reached rift ratio (F/H) of 0.5 at approx. 26, 57, and 78 days, respectively. The presence of any kind of package delayed fracturability loss by at least eight folds at 80% RH. The pecans stored in ML did not experience a significant change in textural attributes.


Asunto(s)
Carya , Polietileno , Humedad , Dureza
3.
Curr Res Food Sci ; 5: 261-271, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35146443

RESUMEN

Postharvest changes in pecan nutmeat color are affected by many factors, both internal and external. The temperature, relative humidity (RH) of the surrounding environment, and storage time are major factors contributing to color deterioration of the nutmeats. Kinetic models have long been employed to provide insights into the physical and chemical changes in food systems; however, no kinetic model has been developed describing the color changes of pecan nutmeats during storage. The objective of this research was to determine the effect of temperature, RH and storage time on pecan nutmeat color change. Pecan nutmeats of three commercially important cultivars (Stuart, Pawnee and Desirable) were subjected to different temperatures (20, 30 and 40 °C) and RH conditions (30, 50, 75% and 80%) for up to 450 days in simulated storage. The observed color changes of the pecan nutmeats were measured as lightness, chroma and hue (LCh). Additionally, the USDA pecan color rating scale was digitized to encourage its use among researchers. It was observed that the change in hue followed a zero-order decay whereas change in lightness and chroma followed a first-order decay. The value of the reaction constants ranged from 0.010 to 1.315 day-1. An Arrhenius model was used to estimate the activation energy (Ea) corresponding to different storage conditions. The values revealed significant effects of temperature, RH and storage days on color degradation. The breakdown of flavonoids and reaction products from Maillard browning could be responsible for the formation of the reddish-brown color observed in degraded nutmeats. The kinetic parameters and models were used to develop a user-friendly online interface for predicting color change depending on selected parameters, with illustrations of the resulting pecan color (https://tinyurl.com/uspecans). The results of this study will aid pecan growers, processors and researchers to predict and visualize changes in color of pecan nutmeats during storage under various conditions of temperature and RH, and duration of storage. Although the study used cultivars Stuart, Pawnee and Desirable, the results likely have more general applicability to other cultivars too.

4.
Foods ; 10(1)2021 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-33477287

RESUMEN

A novel produce wash consisting of pelargonic acid (PEL) emulsions was tested on tomatoes contaminated with a five-serovar Salmonella enterica cocktail. Ability to reduce contamination on the inoculated tomato surface, as well as mitigation of subsequent cross-contamination to uninoculated tomatoes washed in re-used/spent wash water were examined. Sanitizer efficacy was also examined over 1 and 7 d storage time (8 °C, recommended for red ripe tomatoes) and in the presence of 0.5% (w/v) organic load. PEL performed statistically the same (p ≤ 0.05) at both 30 mM and 50 mM concentrations and resulted in greater than 1, 5 and 6 log CFU/g Salmonella reductions at 0 h, 1 d and 7 d, respectively, when compared to a water-only or no rinse (NR) treatment. This was also a significantly greater reduction than was observed due to chlorine (sodium hypochlorite) and peroxyacetic acid (PAA) at all time points (p ≤ 0.01). Organic load had no impact on sanitizer efficacy for all examined treatments. Finally, PEL had a deleterious impact on tomato texture. At 1 d, ca. 5 N and 7 N were required to achieve tomato skin penetration and compression, respectively, compared to >9 N and 15 N required by all other treatments (p ≤ 0.05). While PEL sanitizers effectively reduced inoculated Salmonella and subsequent transfer to uninoculated tomatoes, reformulation may be necessary to prevent deleterious quality impacts on produce.

5.
Food Chem ; 342: 128345, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33268176

RESUMEN

The effect of thermal treatment of blueberry was investigated using a designed grinding and continuous packaging system under oxygen-free conditions. The grinding, packaging, and heating at 90 °C for 30 min under anaerobic condition were compared to heating under aerobic conditions, showing complete inactivation of oxidative enzymes. Heating without oxygen retained anthocyanins and ascorbic acid whereas heating in atmospheric air does not. Delphinidin glycoside was mostly influenced by oxygen deficiency during heating, followed by petunidin and malvidin glycosides. The differences in oxygen sensitivity may be closely associated with the number of hydroxylation in the B ring. The result of anthocyanin led to higher antioxidant activity and redness values of purees heated without oxygen than purees heated with oxygen. Consequently, thermal processing under oxygen-free condition can prevent oxidation of anthocyanin, resulting in higher retention of color and nutritional values of blueberry products.


Asunto(s)
Antocianinas/análisis , Antioxidantes/análisis , Ácido Ascórbico/análisis , Arándanos Azules (Planta)/química , Arándanos Azules (Planta)/enzimología , Manipulación de Alimentos , Calor , Aerobiosis , Arándanos Azules (Planta)/metabolismo , Pigmentación
6.
J Food Sci ; 85(10): 3020-3025, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32856294

RESUMEN

Pecan shells were used as a source of smoke for cooked chicken breast and compared with samples smoked with hickory, mesquite, and apple tree wood. The wood moisture content ranged from 7.94% to 11.43%, whereas ash ranged from 0.97% to 3.11%. The particle size varied among the smoke sources, with chopped pecan shells having more pieces in the "coarse" category. Several properties related to quality of the cooked meat were measured including moisture content, water activity, color, cook loss, expressible moisture, and maximum shear force. Moisture content ranged from 70.13% to 71.72%, whereas pH ranged from 6.39 to 6.43. Chicken breasts smoked with pecan shells were darker (L* = 72.86 compared to 74.94 to 76.57) and slightly redder (a* = 5.71; b* = 25.70) than other samples. Color development was localized to the surface of the meat. Cooking loss did not differ significantly among the samples (26.13% to 27.03%) nor did expressible moisture (9.68% to 11.87%). Meat tenderness was assessed by shear values, but did not differ among the samples. Consumer panels showed that all samples were well liked. Samples smoked with mesquite had slightly lower scores for flavor and overall likability, whereas the scores for samples smoked with hickory, apple, or pecan shells were no different. PRACTICAL APPLICATION: Many meat products are cooked in the presence of smoke produced from burning hardwoods. This work shows that smoke can be produced from waste pecan shells, resulting in chicken breast with similar yield, texture, moisture retention, and acceptability as that smoked with hickory, mesquite, or apple tree wood.


Asunto(s)
Carya , Culinaria/métodos , Carne/normas , Animales , Pollos , Color , Humanos , Gusto
7.
J Colloid Interface Sci ; 545: 317-329, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30897428

RESUMEN

HYPOTHESIS: Nanocellulose (NC) has been a topic of significant interest due to its multiple applications, including that as a potential food ingredient. Due to the viscous property of NC and its potential use as emulsion stabilizers, presence of NC in food may affect properties and digestion of lipid emulsions systems. In this study, the behavior of three types of nanocellulose and its influence on lipid emulsions during digestion were investigated. EXPERIMENTS: The changes in physicochemical characteristics (including particle size, microstructure, viscosity, and zeta potential) of the emulsions as well as the amount of free fatty acid released were studied and compared among the addition of different types/concentrations of fiber as well as digestion phases. FINDINGS: The colloidal stability of three types of NC differed during each digestion phase. Specifically, cellulose nanocrystals (CNC) formed hydrogel networks during the gastric phase, resulting in increased digesta viscosity. Cellulose nano-fibrils (CNF) were stable and had no morphological changes during digestion. TEMPO-oxidized cellulose nano-fibrils (TEMPO-CNF) de-swelled and showed aggregation at the gastric phase. Results showed that all three types of nanocellulose at high concentrations (1% CNF, 0.25-0.36% TEMPO-CNF or 2-3% CNC) delayed initial in vitro digestion of emulsions, though the final lipolysis extent was nearly the same amongst all (47-55%).

8.
J Sci Food Agric ; 99(2): 816-823, 2019 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-30003541

RESUMEN

BACKGROUND: Consumer demand for low-fat foods has been increasing as a result of attempts to reduce obesity and chronic diseases. Bovine heart was defatted using supercritical CO2 (SC-CO2 ) at different pressures together with solvent extraction to produce a protein-based functional ingredient for low-fat food products. Thermal and functional characteristics of control and defatted samples were compared. RESULTS: Supercritical CO2 treatment at high pressure results in more removal of fat, producing a protein-rich defatted bovine heart (DBH). The differential scanning calorimeter (DSC) thermograms and SDS-PAGE bands for SC-CO2 -treated DBHs were similar to those of the control sample, indicating high protein stability and better functionality. Hexane-treated DBH showed no major thermal peaks and very diffuse bands in SDS-PAGE, indicating denaturation of proteins during solvent extraction. No denaturation of proteins in SC-CO2 -treated DBHs resulted in significantly higher water/oil absorption capacities (3320.00 and 2630.00 g kg-1 , respectively), total soluble solids (822.20 and 208.71 g kg-1 at pH 3.5 and 6.5, respectively), foaming capacities (149.37%), and emulsion activity (66.89%) than the hexane-treated DBH. CONCLUSION: Supercritical CO2 treatment of DBH led to higher thermal stability and functional properties than the control and hexane-treated DBH. Defatted bovine heart using SC-CO2 can be a functional ingredient for various low-fat and high-protein food products for health-conscious consumers. © 2018 Society of Chemical Industry.


Asunto(s)
Cromatografía con Fluido Supercrítico/métodos , Grasas/aislamiento & purificación , Manipulación de Alimentos/métodos , Carne/análisis , Animales , Dióxido de Carbono/química , Bovinos , Grasas/análisis , Corazón , Miocardio/química , Miocardio/metabolismo
9.
J Food Sci ; 83(12): 3019-3026, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30440087

RESUMEN

The effects of added water (1:0 up to 1:4 apple:water w/v) and grinding temperature on browning and antioxidant capacity of apples were investigated. Grinding apple with addition of water decreased browning and loss of antioxidant activity when ground with water up to 1:3 ratio. Browning, antioxidant capacity, major phenolic compounds (chlorogenic acid, epicatechin, and procyanidin B2), and ascorbic acid in ground apple with water (1:1) were evaluated at grinding temperatures from 5 °C to 45 °C. The degradation of antioxidant activity, phenolic compounds, and ascorbic acid followed first-order kinetics. The temperature-dependent degradation was adequately modeled using the Arrhenius equation, and kinetic parameters such as k, t1/2 , Q10 , and Ea indicated that the grinding temperature was a key factor affecting retention of antioxidant activity, phenolics, and ascorbic acid contents in apple. PRACTICAL APPLICATION: The phenolic compounds and antioxidant activity of fruits and vegetables can be altered by processing such as thermal treatments and grinding. Therefore, it is important to evaluate and predict the quality characteristics of the fruits as affected by processing conditions. In this study, we found grinding conditions retard the changes in color and loss in phenolic compounds and antioxidant activity of ground apples. This new finding can be helpful for engineers and scientists to control and optimize the grinding system by retaining the high nutritional values of apple products.


Asunto(s)
Ácido Ascórbico/análisis , Manipulación de Alimentos , Malus/química , Fenoles/análisis , Temperatura , Agua/química , Antioxidantes/análisis , Biflavonoides/análisis , Catequina/análisis , Ácido Clorogénico/análisis , Color , Frutas/química , Valor Nutritivo , Proantocianidinas/análisis
10.
J Food Sci Technol ; 55(7): 2712-2720, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30042587

RESUMEN

The consumer demands for low fat foods are increasing to reduce obesity and chronic diseases. Low-fat tofu (LFT) was prepared using soy flours treated with supercritical CO2 (SC-CO2) at pressures of 10, 20, and 30 MPa. After SC-CO2 treatment, the residual oil contents of the soy flours were 12.07, 8.12, and 1.64%, respectively, whereas that of the control soy flour was 18.20%. The objective of this study was to investigate the yield and quality characteristics of LFTs, compared to the control tofu. All SC-CO2-treated LFTs had significantly higher protein and moisture contents than the control tofu. The yields (g/100 g soy flour) of SC-CO2-treated tofu were 442.69, 507.44, and 535.47 g, respectively, at three fat levels, whereas the yield was 385.23 g in case of the control tofu. The SC-CO2-treated LFTs had softer textural attributes due to increasing moisture contents. In addition, the LFTs obtained higher sensory scores owing to softer texture and lower beany flavor than control sample. SC-CO2-treated soy flours showed higher solubility in soy milk, leading to higher yield, produced softer texture of tofu, and increased nutritional value with low fat and high protein content.

11.
Carbohydr Polym ; 196: 146-153, 2018 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-29891281

RESUMEN

Nano-fibrillated cellulose (NFC) is of interest in several fields due to its unique physical properties derived from its nanoscale dimensions. NFC has potential use in food systems as a dietary fiber that increases viscosity and limit diffusion of glucose. This study focused on the effects of added NFC on solution viscosity, starch digestion and glucose absorption. NFC did not affect α-amylase and α-glucosidase activity, but significantly retarded glucose diffusion, delayed amylolysis and reduced the amount of glucose released during in vitro digestion of starch. Specifically, 1% NFC retarded ∼26.6% of glucose released during the amylolysis process. The greatly increased viscosity of NFC at concentrations >0.5% was thought to be the main mechanism for its potential hypoglycemic effects. NFC suspensions also had higher glucose adsorption capacity than those containing cellulose. In addition, NFC bound 35.6% of the glucose when the initial glucose level was within the range of 5-200 mM. These results suggest that NFC may be useful for building viscosity in food products and serving to inhibit glucose absorption in vivo in starch-containing products.

12.
J Food Sci ; 83(3): 822-830, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29355948

RESUMEN

Raw almonds are a major commodity, yet much is unknown about how storage conditions determine their shelf life. The storage stability, as measured by consumer assessments and chemical measures, of raw almonds was determined for samples stored in cardboard boxes and polypropylene packaging for 2 years at 4, 15, 25, and 35 °C, and at 50% and 65% relative humidity (RH). Samples stored in unlined cartons always failed (>25% rejection) before their counterparts stored in polypropylene bags under identical environmental conditions. Models determined that polypropylene packaging (as opposed to unlined cardboard cartons) extended the time until sample rejection by more than 7 months. Temperature and RH were both negatively associated with storage time until failure. Flavor was a greater contributor to consumer acceptability than texture or odor, while peroxide values and free fatty acids were of greater importance in predicting raw almond consumer quality than measures of conjugated dienes or 2-thiobarbituric acid-reactive substances. PRACTICAL APPLICATION: The results of this study will allow almond producers to determine packaging types and environmental storage conditions that provide shelf life of a specified time.


Asunto(s)
Almacenamiento de Alimentos , Nueces/química , Prunus dulcis , Adolescente , Adulto , Comportamiento del Consumidor , Femenino , Embalaje de Alimentos , Humanos , Masculino , Odorantes , Gusto , Temperatura , Adulto Joven
13.
J Sci Food Agric ; 98(10): 3851-3859, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29363771

RESUMEN

BACKGROUND: Roasting is a critical step in chocolate processing, where moisture content is decreased and unique flavors and texture are developed. The determination of the degree of roasting in cocoa beans is important to ensure the quality of chocolate. Determining the degree of roasting relies on human specialists or sophisticated chemical analyses that are inaccessible to small manufacturers and farmers. In this study, an electronic nose system was constructed consisting of an array of gas sensors and used to detect volatiles emanating from cocoa beans roasted for 0, 20, 30 and 40 min. The several signals were used to train a three-layer artificial neural network (ANN). Headspace samples were also analyzed by gas chromatography/mass spectrometry (GC/MS), with 23 select volatiles used to train a separate ANN. RESULTS: Both ANNs were used to predict the degree of roasting of cocoa beans. The electronic nose had a prediction accuracy of 94.4% using signals from sensors TGS 813, 826, 822, 830, 830, 2620, 2602 and 2610. In comparison, the GC/MS predicted the degree of roasting with an accuracy of 95.8%. CONCLUSION: The electronic nose system is able to predict the extent of roasting, as well as a more sophisticated approach using GC/MS. © 2018 Society of Chemical Industry.


Asunto(s)
Cacao/química , Nariz Electrónica , Cromatografía de Gases y Espectrometría de Masas/métodos , Semillas/química , Culinaria , Redes Neurales de la Computación , Compuestos Orgánicos Volátiles/química
14.
J Food Sci ; 83(1): 84-92, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29243815

RESUMEN

This study evaluated the effects of grinding at atmospheric pressure (control), under vacuum (∼2.67 kPa), or with modified atmosphere (N2 and CO2 ) on the browning, antioxidant activity, phenolics, and oxidative enzyme activity of apples as a function of time. The control group was affected most, showing distinct browning and losing most of the antioxidant activity and concentrations of the main phenolic compounds. The modified atmosphere groups retained color, antioxidant activity, and phenolic compounds better than the control group. Least changes were obtained with vacuum grinding, particularly in terms of preventing enzymatic browning and oxidation of antioxidants apples. At 12 h after grinding, vacuum-ground apples retained total phenolic contents 5.32, 1.54, and 1.49 times higher than control, nitrogen gas, and carbon dioxide gas-ground samples, respectively. The oxidative enzyme activity, including that of polyphenol oxidase and peroxidase, decreased in the control and modified atmosphere group, but they were maintained in the samples ground under the vacuum. PRACTICAL APPLICATION: In this study, we found that grinding with modified atmosphere or vacuum conditions could effectively prevent browning as well as loss of phenolic compounds and antioxidant activity of ground apples. These results can help scientists and engineers build better grinding systems for retaining nutrient and quality factors of ground apples. In addition, these results may be useful to other fruit and vegetable industries that wish to retain fresh-like quality and nutritional value during grinding and storage.


Asunto(s)
Antioxidantes/análisis , Manipulación de Alimentos/métodos , Frutas/química , Reacción de Maillard , Malus , Dióxido de Carbono , Catecol Oxidasa/metabolismo , Aditivos Alimentarios , Frutas/enzimología , Nitrógeno , Valor Nutritivo , Oxidación-Reducción , Peroxidasa/metabolismo , Fenoles/análisis , Vacio
15.
J Texture Stud ; 49(3): 286-292, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29052847

RESUMEN

It has been difficult to produce acceptable pecan butters as the high oil content results in a product that flows and separates too easily. The objective of this work was to create pecan butters with varying oil levels (50-70%) and determine which would give the most acceptable product. Consumers rated pecan butters with 55-60% oil the most acceptable, whether roasted or not. Acceptability varied most in terms of texture and spreadability, but not flavor. Under large deformation firmness varied from 51.8 g (70% oil) to 4,880 g (50%) oil, while "spreadability" ranged from 19.2 to 7748 (g/s). Samples with 70% oil had the lowest viscosity and were Newtonian. Pecan butters with 50-55% oil had high viscosity and were shear thinning. Yield stress decreased with oil content, ranging from 0.014 to 500 Pa. The storage modulus (G') increased from ∼7 Pa for samples with 70% oil up to 260,000 Pa for those with 50% oil. In conjunction, tan δ decreased from 1 to 0.07, showing the products take on much more solid-like behavior as oil is removed. In conclusion, the rheological properties of pecan butter were quite sensitive to the amount of oil in the product. Differences in acceptability were primarily due to "texture" and "spreadability," suggesting there is a limited range of firmness and spreadability that consumers will deem acceptable. PRACTICAL APPLICATIONS: There has been considerable demand for butters and spreads made from a variety of culinary nuts. Pecans generally have too much oil (∼70%) to make a product with proper consistency and stability. In this study, some of the oil was removed to overcome this problem. It was found that pecan butter with 55-60% oil was most acceptable to consumers and with the level of firmness, yield stress, and spreadability most similar to commercial nut butters. The oil was relatively simple to remove from unroasted nuts, thus manufacturers could easily produce more acceptable pecan butter for the market.


Asunto(s)
Mantequilla/análisis , Carya , Tecnología de Alimentos , Aceites de Plantas/análisis , Humanos , Gusto
16.
J Food Sci Technol ; 54(13): 4405-4415, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29184247

RESUMEN

Thunbergia laurifolia leaves were dried by freeze drying (FD) and microwave heat pump dehumidified air drying (MHPD). The dried leaves were stored in polypropylene (PP) or aluminum laminated pouches (ALP) at 15, 25 or 35 °C and 60% RH. The samples were held for 180 days to observe changes in moisture content, color, total phenolics, antioxidant activity, catechin and caffeic acid. In general, samples in PP had a greater increase in moisture. Total phenolics content and ferric-reducing antioxidant power values increased for 120 days, then decreased thereafter. After 180 days, both FD and MHPD samples packaged in ALP and stored at 15 °C had the greatest total phenolics, antioxidant activity and bioactive compounds amongst the storage conditions. The first-order equation best described degradation behavior of catechin and caffeic acid for both drying technologies investigated.

17.
J Food Sci Technol ; 54(8): 2485-2493, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28740306

RESUMEN

Defatted soy flour is a potential source of food protein, amino acids, ash and isoflavones. The supercritical carbon dioxide (SC-CO2) and a traditional organic solvent extraction methods were used to remove fat from soy flour, and the quality characteristics of a control soy flour (CSF), defatted soy flour by SC-CO2 (DSFSC-CO2) and defatted soy flour by an organic solvent (DSF-OS) were compared. The SC-CO2 process was carried out at a constant temperature of 45 °C, and a pressure of 40 MPa for 3 h with a CO2 flow rate of 30 g/min. The DSFSC-CO2 had significantly higher protein, ash, and amino acids content than CSF and DSF-OS. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated that CSF and DSFSC-CO2 had protein bands of similar intensity and area that indicated no denaturation of protein, whereas DSF-OS showed diffuse bands or no bands due to protein denaturation. In addition to higher nutritional value and protein contents, DSFSC-CO2 showed superior functional properties in terms of total soluble solids content, water and oil absorption, emulsifying and foaming capacity. The SC-CO2 method offers a nutritionally and environmentally friendly alternative extraction processing approach for the removal of oil from high-protein food sources. It has a great potential for producing high-protein fat-free, and low-calorie content diet than the traditional organic solvent extraction method.

18.
J Sci Food Agric ; 97(10): 3211-3219, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27925210

RESUMEN

BACKGROUND: Dried Thunbergia laurifolia leaves are usually prepared using tray drying, resulting in products that have lost substantial amounts of bioactive compounds and antioxidant activity. The maturity of the raw material, blanching techniques and drying methods were investigated in order to select the best condition to produce high qualities of dried T. laurifolia leaves. RESULTS: The 1st stage of maturity was selected and steam-microwave blanching (SMB) for 4 min was adequate for blanching leading to the maximum recovery of bioactive compounds. The modified Halsey model was the best desorption isotherm model. A new drying model proposed in this study was the best to fit the drying curves as compared to five common drying models. Moisture diffusivities were increased with the increase of drying temperature when combining SMB and heat pump-dehumidified drying. Microwave heat pump-dehumidified drying (MHPD) provided the shortest drying time, high specific moisture extraction rate (SMER) and could reduce drying time by 67.5% and increase caffeic acid and quercetin by 51.24% and 60.89%, respectively. CONCLUSION: MHPD was found to be the best drying method and provided the highest antioxidant activity and bioactive compounds content, high SMER and short drying time. © 2016 Society of Chemical Industry.


Asunto(s)
Acanthaceae/química , Conservación de Alimentos/métodos , Hojas de la Planta/química , Antioxidantes/análisis , Desecación , Flavonoides/análisis , Microondas , Vapor/análisis
19.
Food Chem ; 216: 234-42, 2017 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-27596414

RESUMEN

The purpose of this study was to evaluate the effect of grinding at different vacuum levels (2.67, 6.67, 13.33, 19.99, and 101.33kPa) on key quality factors of apple. In the control apple, ground at atmospheric pressure of 101.33kPa, the antioxidant activities rapidly decreased within the first 30min, then plateaued thereafter, while enzymatic browning increased. When apples were ground and held under vacuum, changes in color and antioxidant activity were much less, and the least change was measured in samples prepared at the lowest pressure. Model fitting of the data showed that antioxidant activity decreased as a function of the logarithm of the absolute pressure. The results from analysis for key phenolic compounds including chlorogenic acid, procyanidin B2, and epicatechin indicated that these compounds were least changed at vacuum grinding at 2.67kPa, compared to atmospheric grinding.


Asunto(s)
Antioxidantes/farmacología , Malus/química , Fenoles/análisis , Biflavonoides/análisis , Catequina/análisis , Ácido Clorogénico/análisis , Color , Proantocianidinas/análisis , Vacio
20.
Food Chem ; 168: 225-32, 2015 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-25172704

RESUMEN

We aimed to determine the effect of encapsulation on the release properties of blueberry extracts during simulated gastrointestinal digestion. An ethanolic pomace extract was microencapsulated with whey protein isolate via spray drying. The in vitro release of monomeric anthocyanins, phenolics and ferric reducing antioxidant activity of the microcapsules (W) were evaluated for the microcapsules and two non-encapsulated systems: ethanolic pomace extract (P) and freeze-dried juice (F). Concentrations of anthocyanin and phenolics were normalised prior to digestion. Results showed that antioxidant activity was in the order of: F>W>P. Regardless of encapsulation, more phenolics were released from W and P than F. Anthocyanin concentration decreased after intestinal digestion for W, but remained constant for P and F. MALDI-MS showed similar spectra for P and F but not for W. The spray-dried product has comparable release characteristics to freeze-dried juice, and may be investigated for food applications.


Asunto(s)
Arándanos Azules (Planta)/química , Extractos Vegetales/química , Antocianinas/análisis , Antocianinas/metabolismo , Antioxidantes/análisis , Antioxidantes/metabolismo , Arándanos Azules (Planta)/metabolismo , Desecación , Digestión , Composición de Medicamentos , Manipulación de Alimentos , Humanos , Modelos Biológicos , Fenoles/análisis , Fenoles/metabolismo , Extractos Vegetales/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
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