Retention Of Antioxidant Activity Research Articles

Total Phenolic Content and Antioxidant Activity of Yacon (Smallanthus Sonchifolius Poepp. and Endl.) Chips: Effect of Cultivar, Pre-Treatment and Drying

Recent studies have associated the consumption of yacon root as a functional plant food with reduced glycemic index and, due to its considerable phenolic acid levels, a protection of cell membranes against free radical damage. This study examined the effect of four different treatments including: (1) storage duration after harvest (one and three weeks after harvest); (2) pre-treatment before drying (untreated, pre-treatment with diluted lime juice); (3) drying method (freeze drying (FD) and convective hot air drying (CHAD)); and (4) cultivar (white and red), on the quality of yacon (Smallanthus sonchifolius Poepp. and Endl.) chips in terms of their total phenolic content (TPC) and antioxidant activity (AA) (ABTS (2,2′-Azino-Bis (3-Ethylbenzothiazoline-6-Sulfonic Acid) Diammonium Salt) radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and ferric reducing antioxidant power (FRAP)). Overall, the chips that were produced using pre-treatment with diluted lime juice and FD had the highest amounts of TPC and AA. Regarding the chips produced by means of CHAD, retention of higher TPC and AA was possible with lime-juice pre-treatment and use of higher hot air temperatures. Moreover, chips produced from the white cultivar had higher TPC and AA than chips produced from the red cultivar.

The Effects of Added Water and Grinding Temperature on Stability and Degradation Kinetics of Antioxidant Activity, Phenolic Compounds, and Ascorbic Acid in Ground Apples.

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.

Assessment of factors influencing the concentration of betacyanin from Opuntia ficus-indica using forward osmosis

Betacyanin is the red-violet pigment possesses potent antiradical and antioxidant properties. Globally, natural colorants have gained much interest than synthetic colours due to their adverse ill effects. The study aimed to assess membrane technology for the concentration of betacyanin pigment from cactus pear employing forward osmosis. The effect of process parameters such as feed and osmotic agent solution (OAS) flowrate and temperature on betacyanin concentration was investigated using factorial design. Maximum concentration of betacyanin was obtained with 150mL/min feed flowrate, 50°C feed temperature, 150mL/min OAS flowrate and 50°C OAS temperature. Further, sodium chloride was the best OAS that concentrated betacyanin from 898 to 1325mg/L with a transmembrane flux of 1.13L/m2h. Physico-chemical characteristics imply high retention of antioxidant activity and other nutrients during concentration process. The results revealed the suitability of forward osmosis for the concentration of betacyanin from Opuntia ficus-indica using cellulose acetate membrane.

Evaluation of the oxidative stability of Chipotle chili (<em>Capsicum annuum</em> L.) oleoresins in avocado oil

Capsicum annuum L. (Chipotle chili) is a natural source of bioactive metabolites with antioxidant properties. The objective of this research was to obtain and characterize the oxidative stability under storage of Chipotle chili oleoresins extracted with cold-pressed avocado oil. The most efficient conditions obtained to extract carotenoids and phenolic compounds were at 1:3 ratio (chipotle chili: avocado oil; w:v) at room temperature in darkness during 48 h. At the end of the harshest conditions (45 °C, 30 days), the extracts were stable to lipid oxidation with a final Totox value of 27.34, a carotenoid preservation of 85.6%, antioxidant activity retention of 80.66% and a color change (ΔE) of 1.783. The kinetic constants obtained were higher for peroxide formation than for carotenoid degradation. The oleoresins obtained could be considered an economic and sustainable alternative to extract carotenoids with good oxidation stability that could be used in foodstuffs.

Maltodextrin: A consummate carrier for spray-drying of xylooligosaccharides

The aim of this study was to evaluate the influence of spray-drying on the powder qualities and microstructures of prebiotic xylooligosaccharides (XOS). The relationships between glass transition temperature (Tg) and XOS retention, moisture content, drying yield as well as specific surface area under different inlet air temperatures and maltodextrin concentrations were investigated. Antioxidant activity retention, hygroscopicity, color attributes, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) of the spray-dried XOS product were also assessed. The results indicated that an increase in inlet air temperature decreased the moisture content, hence the Tg value was increased. Higher maltodextrin concentration increased the Tg value, and was attributed to the molecular weight increase. The wall deposition was a tendency to occur when the temperature beyond the Tg, reduced the drying yield. Higher temperature and wall deposition promoted the decomposition of XOS into monosaccharide. The crust formation rate of droplets and stickiness of microparticles were affected by Tg, and hence, influenced the specific surface area. The antioxidant activity retention of XOS exhibited a concentration-dependent behavior. The hygroscopicity of the microparticles could be reduced by both of the low inlet air temperature and high maltodextrin concentration. According to the results of color attributes, XRD and SEM, the particles were colorless and amorphous, and tended to become more spherical and scattered with the addition of maltodextrin. The FT-IR analysis confirmed that no chemical reaction occurred between XOS and agent, which indicated that maltodextrin is a promising carrier for producing bioactive XOS powder.

Retention of alkylresorcinols, antioxidant activity and fatty acids following traditional hulled wheat processing

This study compared alkylresorcinols, fatty acids and antioxidant activity retention following hulled wheat processing by traditional and modern plants. Glume removal and kernel crushing were considered as characterising steps.Samples were collected from two traditional einkorn wheat bulgur processing plants in Turkey, one emmer wheat processing plant in Armenia and a modern two stage processing plant in Italy, also including pearling.Whole kernels showed higher alkylresorcinol contents (759–1037 mg kg−1 dm) and antioxidant activity with respect to the correspondent crushed products. Following crushing a decrease of total alkylresorcinol content was observed, with lowest amounts detected in the semolina-like fractions. Pearling did not determine a significant decrease of alkylresorcinols of the pearled output. However the waste obtained from pearling, mainly composed of bran parts, showed the highest alkylresorcinol amount (1493 mg kg−1 dm) and antioxidant activity. The waste from pearling resulted also the richest fraction of unsaturated alkylresorcinol homologues and unsaturated fatty acids. Among fatty acids, C18:2, C18:1 and C16 resulted the most abundant compounds in all fractions.All the plants showed similar performance, with higher alkylresorcinol decreases due to the loss of specific parts of kernel, such as germ and bran.

Adsorption and Recovery of Polyphenolic Flavonoids Using TiO2-Functionalized Mesoporous Silica Nanoparticles.

Exploiting specific interactions with titania (TiO2) has been proposed for the separation and recovery of a broad range of biomolecules and natural products, including therapeutic polyphenolic flavonoids which are susceptible to degradation, such as quercetin. Functionalizing mesoporous silica with TiO2 has many potential advantages over bulk and mesoporous TiO2 as an adsorbent for natural products, including robust synthetic approaches leading to high surface area, and stable separation platforms. Here, TiO2-surface-functionalized mesoporous silica nanoparticles (MSNPs) are synthesized and characterized as a function of TiO2 content (up to 636 mg TiO2/g). The adsorption isotherms of two polyphenolic flavonoids, quercetin and rutin, were determined (0.05-10 mg/mL in ethanol), and a 100-fold increase in the adsorption capacity was observed relative to functionalized nonporous particles with similar TiO2 surface coverage. An optimum extent of functionalization (approximately 440 mg TiO2/g particles) is interpreted from characterization techniques including grazing incidence X-ray scattering (GIXS), high-resolution transmission electron microscopy (HRTEM), and nitrogen adsorption, which examined the interplay between the extent of TiO2 functionalization and the accessibility of the porous structures. The recovery of flavonoids is demonstrated using ligand displacement in ethanolic citric acid solution (20% w/v), in which greater than 90% recovery can be achieved in a multistep extraction process. The radical scavenging activity (RSA) of the recovered and particle-bound quercetin as measured by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay demonstrates greater than 80% retention of antioxidant activity by both particle-bound and recovered quercetin. These mesoporous titanosilicate materials can serve as a synthetic platform to isolate, recover, and potentially deliver degradation-sensitive natural products to biological systems.

Quality and bioaccessibility of total phenols and antioxidant activity of calçots (Allium cepa L.) stored under controlled atmosphere conditions

Calçots are the floral stems of the second-year onion (Allium cepa L.) resprouts with economic importance in Spain, where they are usually consumed roasted. The effect of two controlled atmospheres (CA) of 2.0% O2+3.5% CO2 (CA1), 1.0% O2+2.0% CO2 (CA2) and air at 1°C for 60 d on the physicochemical, nutritional and sensory quality of calçots were studied. In addition, the total phenolic content (TPC) and the antioxidant activity (AA) of roasted calçots were evaluated after an in vitro gastrointestinal (GI) digestion. Both CA regimes reduced the respiration rate of the stored product without causing physiological disorders. The TPC and AA of calçots increased during storage. Storage for 60 d in CA2 resulted in the highest AA by DPPH assay, whereas calçots stored in air for 60 d showed the highest TPC and AA by FRAP assay. Calçots stored in air for 30 d and fresh harvested sample presented the highest total flavonoids values. After 30 d of storage, calçots stored in CA had a higher liking degree than calçots stored in air. The AA of digested calçots decreased drastically after in vitro GI digestion in comparison to the non-digested samples. However, TPC increased after digestion. Roasted calçots stored in CA1 for 30 d showed the highest TPC and AA retention in the intestinal phase. CA could be a postharvest strategy for the storage of calçots.

Composite flour blends: Influence of particle size of water chestnut flour on nutraceutical potential and quality of Indian flat breads

Different sieve particle sizes P1 (Whole), P2 (≤0.212 mm) and P3 (≤0.125 mm) of water chestnut flour (WCF) were studied for proximate composition, mineral content, physico-chemical, functional, pasting and antioxidant properties in comparison to refined wheat flour (WF). WCF had significantly higher levels of fiber, resistant starch, mineral (K, Mg, Zn, and Cu), phenolics and flavonoids than WF in the order (P1 > P2 > P3 > WF). Increase in flour fineness decreased antioxidant activity (P1 > P2 > P3) with P1 having highest phenolic (4.72 mg GAE/g), flavonoid (2.46 mg QE/g) content. Pasting properties of P1 were significantly lower than WF but significantly increased with increase in flour fineness. Quality of flat bread produced from WCF-WF blends significantly varied with particle size and blending. Bake loss and baking time significantly decreased while shrinkage increased with decrease in particle size. L* value decreased with blending but showed an irregular trend with variation in particle size. (WF > P2 ≥ P3 > P1). Baking decreased DPPH scavenging activity more in WF bread (46.68%) than WCF bread (P1 = 17.71%, P2 = 16.45%, P3 = 19.63%). Baking decreased total phenolic and flavonoid content by 49 and 20% in wheat & 38 and 16% in WCF respectively while significantly increased the resistant starch content in the order (P3 > P2 > P1 > WF). This shows better retention of antioxidant activities and greater stability of WCF phenolics than WF phenolics during baking. Sensory analysis showed WCF breads had fair acceptability due to their characteristic flavor. Thus, gluten free WCF bread is also antioxidant rich with ample resistant starch content than WF breads.

Effect of Digestive Enzyme Treatment on Antioxidant Properties of Germinated Green Gram Fortified with Minerals

The antioxidant activity (AA) of green gram germinated in mineral‐fortified water (with iron at 100 or 200 mg/100 mL or zinc at 50 or 100 mg/100 mL), cooked under pressure (PC), or microwaved and subjected to digestive enzyme treatment was determined by using three assay methods. Total AA showed that dehulled grains (DG) had higher AA than whole grains (WG). Cooking reduced the AA in both methods compared with raw grains with a lower percent retention of AA, although significant variations were not found between methods. The percent retention of AA in postdigestion samples was 22.68–51.39 (DG) and 15.67–44.0 (WG). Free radical scavenging activity indicated a different pattern, in which WG exhibited higher AA than DG and, among cooking methods, PC grains had higher activity. A reducing‐power assay showed similar results: DG had lower and PC samples had higher AA. Postdigestion AA of WG was higher for cooked than raw samples, although DG showed the opposite trend. In all cases, samples fortified with iron showed less AA because of prooxidant action of iron. In all assays, postdigestion samples had less activity than predigested extracts. In conclusion, germinated grains showed high AA, influenced by the presence of minerals, dehulling process, and cooking.

Wheat-water chestnut flour blends: effect of baking on antioxidant properties of cookies.

Proximate composition, mineral content, functional, pasting and antioxidant properties of water chestnut flour (WCF) were compared with refined wheat flour. WCF showed higher phenolic (4.25gGAE/1000g), flavonoid (1.92g QE/1000g) and mineral content (K, Mg, Zn, Cu) than wheat flour. WCF showed greater retrogradation tendency but lower peak viscosity than wheat flour. Wheat flour - WCF blends and cookies were evaluated for water activity, physical & textural properties. Water activity of cookies decreased significantly (0.415-0.311) with increase in level of WCF in wheat flour. Total phenolic content, flavonoid content and antioxidant activity (DPPH• scavenging capacity, FRAP) of WCF - wheat flour blends as well as their cookies was also determined. Baking led to a greater increase in DPPH• scavenging capacity of WCF cookies (33.8%) than WF cookies (25%). Baking had a similar effect on FRAP value. Wheat flour cookies showed a decrease of 51%, and 62% while WCF cookies showed a decrease of 36%, and 34% in TPC and TFC values respectively. WCF cookies thus showed better retention of antioxidant activities suggesting greater stability of WC phenolics than wheat phenolics. Sensory analysis showed cookies made from water chestnut (100%) had fair acceptability due to their characteristic flavor. Thus, water chestnut flour serves both as a gluten free as well as antioxidant rich flour for production of cookies.

Encapsulation of antioxidant peptide enriched casein hydrolysate using maltodextrin-gum arabic blend.

Antioxidant peptide enriched casein hydrolysate (AO-CH) are receiving increasing attention due to their potential as functional ingredient. Encapsulation of AO-CH using maltodextrin-gum arabic (MD/GA) as wall material could represent an attractive approach to overcome the problems related to their direct application. Encapsulation parameter were optimized using different ratio of core to coat and proportion of coating material (10:0, 8:2, 6:4) under varying pH (2-8) for encapsulation efficiency (EE).The preparation P3 resulted in maximum EE (87%) using core to coat ratio 1:20, at pH 6.0 with 8:2 MD/GA ratio. The encapsulated preparation showed reduced bitterness (p<0.05) compared to the casein hydrolysate together with maximum retention of antioxidant activity (93%). Further, the narrow range of particle size, indicates their better stability and represents a promising food additive for incorporation in food.

Mathematical Modeling and Numerical Simulation for Predictive Retention of Antioxidant Activity of Grape Juice Pasteurized with Continuous Flow Ohmic Heating

This study was aimed to simulate and validate the temperature distribution and antioxidant levels of grape juice pasteurized at different flow rates using a continuous flow ohmic heater. The outlet temperature values of grape juice products at 60°C, 70°C, and 80°C were controlled by applying different electric fields and resident times. The electrical conductivity of grape juice estimated for computational modeling showed a linear correlation with temperature. Numerical simulation of ohmic heating was conducted via finite element method (FEM) codes using the commercial software COMSOL Multiphysics 4.1. The simulation code included ohmic heating, incompressible k-Iµ turbulent flow, heat transfer, chemical reaction, and convection and diffusion modules in a transient state. The outlet temperature values in the simulation had a good agreement with experimental data within an error of 4.4°C. Model predictions were higher than the experimental data because of no consideration of convective heat loss. In addition, the experimental observations and simulated values of antioxidants levels after ohmic heating were consistent, with R 2 > 0.97. These results indicated that the developed model was reliable and suitable for prediction of nutritional values of grape juice pasteurized by ohmic heating.

Effect of different cooking methods on retention of antioxidant activity of bioactive compounds of fox nut (Euryale ferox) seeds incorporated in chicken meat bites

The aim of this study was to elucidate the effect of different cooking methods on the retention of antioxidant activity (AOA) of bioactive compounds of processed fox nut seeds (Makhana) incorporated in chicken meat bites. A total four treatments were assigned (i) steaming (T1); (ii) microwave cooking (T2); (iii) baking (T3); and (iv) microwave + convection cooking (T4). All samples contained makhana powder @ 1.0% along with other seasonings as per standard formulation. Results indicated that the bioactive compounds analyzed were in general much higher in T2 than that found in T4>T1>T3. T2 samples contained total flavonoids, β-carotene, α-tocopherol acetate and Vit-C of 87.44, 16.18, 10.66, 2.08 μg/g, respectively. Gallic acid (47.68 μg/g) and reutin (28.18 μg/g) contents were also highest in T2. Greatest antioxidant activity (AOA) was found in T2 samples though extracts from other samples were also showed very good antioxidant activity on ABTS+, DPPH and superoxide anion scavenging assays. TBARS, FFA contents and peroxides formation were lowest in T2 samples. In respect to sensory attributes, it was better maintained for T1 sample. Finally, it was concluded that though microwave cooking retained major bioactive compounds and exerted potent AOA, but products processed employing steam cooking shown to have better sensory quality.

Microencapsulation of grape (Vitis labrusca var. Bordo) skin phenolic extract using gum Arabic, polydextrose, and partially hydrolyzed guar gum as encapsulating agents

Bordo grape skin extract was microencapsulated by spray-drying and freeze-drying, using gum arabic (GA), partially hydrolyzed guar gum (PHGG), and polydextrose (PD) as encapsulating agents. Total phenolics and total monomeric anthocyanin, antioxidant activity, color, moisture, water activity (aw), solubility, hygroscopicity, glass transition temperature (Tg), particle size, and microstructure of the powders were evaluated. The retention of phenolics and anthocyanins ranged from 81.4% to 95.3%, and 80.8% to 99.6%, respectively, while the retention of antioxidant activity ranged from 45.4% to 83.7%. Treatments subjected to spray-drying had lower moisture, aw, and particle size, and greater solubility, while the freeze-dried samples were less hygroscopic. Tg values ranged from 10.1 to 52.2°C, and the highest values corresponded to the spray-dried microparticles. The spray-dried particles had spherical shape, while the freeze-dried powders showed irregular structures. The spray drying technique and the use of 5% PHGG and 5% PD has proven to be the best treatment.

Selection of Process Conditions for High Pressure Pasteurization of Sea Buckthorn Juice Retaining High Antioxidant Activity

Sea buckthorn berries juice is a nutritious beverage, rich in vitamin C and carotenoids with high antioxidant activity. The main requirements for a freshly squeezed sea buckthorn juice production are the cloud stability and antioxidant activity retention after processing. Appropriate process technologies and conditions have to be applied in order to inactivate pectin methyl esterase (PME), responsible for cloud loss, while maintaining the nutritional characteristics and antioxidant activity of the juice. The objectives of the present work were to study and model the effect of thermal treatment and high pressure (HP) processing on the inactivation kinetics of endogenous PME and on total antioxidant activity alteration. Thermal treatment significantly affected PME inactivation and residual antioxidant activity. Processing even at mild process conditions (60 °C for 1 min) resulted in 2.5-fold antioxidant activity reduction and 50 % PME inactivation compared to untreated sample. Pressure and temperature acted synergistically for PME inactivation that followed first-order kinetics with a residual PME activity at all pressure–temperature combinations used (200–600 MPa and 25–35 °C). The effect of temperature and pressure on the inactivation rate constants was expressed through the activation energy and activation volume, respectively. Values of 163 kJ/mol and −17 mL/mol at reference pressure of 600 MPa and reference temperature of 35 °C were estimated, respectively. Antioxidant activity of the samples was expressed through the determination of the effective concentration (EC50). A slight increase in sea buckthorn antioxidant activity when applying pressures (200–600 MPa) at ambient temperature (25 °C) was observed compared to the corresponding value of untreated juice. Processing at higher temperatures did not significantly alter the total antioxidant activity of sea buckthorn juice. For sample treated at 600 MPa–35 °C for 5 min, a 5 % reduction of total antioxidant activity was observed. These conditions are proposed as effective process conditions for sea buckthorn juice cold pasteurization, based on the higher antioxidant activity retention and simultaneous PME inactivation.

Effect of drying techniques on the retention of antioxidant activities of Saskatoon berries

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P&lt;0.05. DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P&lt;0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P&lt;0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P&lt;0.05.

Effect of drying techniques on the retention of antioxidant activities of Saskatoon berries

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P&lt;0.05. DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P&lt;0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P&lt;0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P&lt;0.05.

Effect of time–temperature conditions and clarification on the total phenolics and antioxidant constituents of muscadine grape juice

Juices have lower quantities of total phenolics content (TPC), anthocyanins, and antioxidant compared to the whole fruit. Furthermore, only low levels of these compounds are extracted from fruit skins during the initial juice processing steps with the majority staying in the skins and seeds. Once the initial juicing starts, degradative reactions begin to convert endogenous polyphenols into new compounds. Even though temperature is the key factor which determines this degradation rate, there is limited information about the temperature at which it begins, and the effects of centrifuging particles before or after thermal processing. The objectives were, first to determine the effects of different time–temperature conditions on the TPC, and antioxidant activity; second, to assess both parameters when the juice was clarified before or after thermal processing. Processing conditions were: 50–80 °C, and 1–30 min as residence time. At temperatures greater than 60 °C, both parameters began to decrease. The optimum processing condition for greatest retention of both parameters was 60 °C and 30 min. TPC and antioxidant activity retention were significantly higher on the juice clarified after thermal processing, compared to the one clarified before. This information can help juice processors and equipment manufacturers to optimize their process and design.

Preparation and characterization of non-aqueous extracts from chilli (Capsicum annuum L.) and their microencapsulates obtained by spray-drying

Antimicrobial, antioxidant, and pro-vitamin properties have been attributed to Capsicum based on the carotenoid and polyphenolic compound content. The aim of this study was to obtain and characterize non-aqueous extracts of Capsicum annuum L. (chilli) using three different oils (corn, sunflower, and safflower) as well as their microencapsulates. Corn extract showed better antioxidant activity and total carotenoid content (as β-carotene) than sunflower and safflower extracts. The extracts were encapsulated by spray-drying with a biopolymers:extract-solution ratio of 4:1 (w/w). The biopolymers were gum Arabic and maltodextrin. In addition, the encapsulation efficiency, mean particle size, morphology, water activity, moisture content, and stability were evaluated for the microcapsules. The retention of antioxidant activity after encapsulation varied from 76% to 80% of its activity in the oily extract, whereas the preservation of carotenoids in microcapsules was between 84% and 86%.