Retention Of Bioactive Compounds Research Articles

Effects of microwave heating on the chemical composition and bioactivity of orange juice-milk beverages

The effect of microwave heating (MH, 65 and 75 °C for 15, 30, and 60 s) on the bioactive compounds, fatty acid profile, and volatile compounds of orange juice-milk beverage (OJMB) was evaluated during 28 days of refrigerated (4 °C) storage. Conventionally pasteurized (75 °C/15 s) and untreated beverages were used as controls. MH-OJMB presented a lower browning index and higher levels of ascorbic acid, total phenolics, and carotenoids, higher antioxidant activity, and greater α-amylase, α-glucosidase, and ACE inhibitory activity than the pasteurized product, similar to the untreated beverage. No significant differences were observed in the volatile organic compounds and fatty acids levels. Lower temperatures (65 °C) and longer process times (60 s) resulted in higher retention of bioactive compounds. MH can be an alternative to conventional pasteurization for OJMB processing.

Effects of Different Drying Methods on the Retention of Bioactive Compounds, On-Line Antioxidant Capacity and Color of the Novel Snack from Red-Fleshed Apples.

The aim of this study was to determine the effect of different drying methods: convective (at 50, 60, 70 °C), vacuum-microwave (at 120, 240, 360, 480 W and 360 W with reduction to 120 W) and hybrid (convective pre-drying at 50, 60, 70 °C followed by vacuum-microwave drying at 120 W) on the quality parameters of novel red-fleshed apple fruit snacks (RFAs), such as phenolics, on-line antioxidant capacity, water activity and color. Drying kinetics, including a temperature profile of dried material, and modified Page model were determined. Freeze-drying was used as a control method. The highest content of bioactive compounds in the samples was retained following freeze-drying, then hybrid, vacuum-microwave and finally convection drying. The antioxidant capacity measured by on-line 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), identified anthocyanins, flavan-3-ols and phenolic acid as the main compounds responsible for this activity. Unfavorable changes in color, formation of hydroxymethylfurfural (HMF) and degradation of polyphenolics were noted along with increasing drying temperature and magnetron power. The red-fleshed apple snacks are a promising high-quality dehydrated food product belonging to functional foods category.

Investigation of physicochemical, nutritional, and sensory qualities of muffins incorporated with dried brewer's spent grain flours as a source of dietary fiber and protein.

Brewers'spent grain(BSG) is the major byproduct of brewing beer, rich in protein and dietary fiber. This study investigated the effect of two drying methods (impingement and hot-air drying) on chemical composition, physicochemical properties, and bioactive compounds of BSGs from three different brewers (BSG1, BSG2, and BSG3), and then evaluated the quality and consumer acceptance of BSG flour fortified muffins. Results showed that impingement drying led to significantly lower moisture content (MC, 1.33-1.87g/100g)andwater activity (aw , 0.04-0.07) of BSGs than hot-air drying (5.44 to 5.57g/100 gand 0.19 to 0.20, respectively). Among different dried BSGs, impingement dried BSG3 achieved the highest protein (18.03g/100 gdry matter [DM]), total phenolic content (TPC, 2.21mg GAE/g DM), radical scavenging activity (RSA, 1.58mg AAE/g DM), and total flavonoid content (TFC, 0.68mg QE/g DM), and retained lighter color (L*, 54.68) and higher total dietary fiber (TDF, 42.40g/100 gDM), which was selected for making BSG-fortified muffins. BSG3 was substituted 1:1 as white: whole wheat flour at three concentrations (10, 15, and 20g/100 gflour mix) for muffins (BSG10, BSG15, and BSG20, respectively). BSG15 provided higher protein (13.11g/100 gDM), TDF (16.88g/100 gDM), and higher bioactive compounds compared to control and retained brighter color of muffin compared to BSG20, showing no difference in firmness and overall liking compared to the control muffin. This study demonstrated that impingement dried BSG could be utilized as a functional ingredient in muffins to add value to the food chain providing nutritional and environmental benefits. PRACTICAL APPLICATION: This study reported the benefit of impingement drying method for the retention of physicochemical quality and bioactive compounds of brewer's spent grains (BSG) produced from three different brewers in comparison with hot-air drying. The study also reported that muffins fortified with BSG flours (15% replacement of wheat flour) yielded a 23% increase in total dietary fiber and 13% increase in protein without affecting consumer acceptance of the products. This information is essential for developing value-added applications of BSG, a byproduct from brewing industry, as a functional ingredient to make nutritive baking goods, such as muffins, for promoting human health.

Red araçá pulp microencapsulation by hydrolyzed pinhão starch, and tara and arabic gums.

Red araçá is a Brazilian native species whose fruits are rich in phenolic acids, flavonoids, anthocyanins, and carotenoids. To preserve the properties of compounds during processing, red araçá pulp (RAP) was encapsulated by hydrolyzed pinhão starch (PS), tara gum (TG), and arabic gum (AG) in different blends in equal proportions, serving as a coating material. Fresh RAP had a gallic acid equivalent of 3098 mg per 100 g of dry weight, 156.29 μg β-carotene per gram of dry weight, total anthocyanins of 18 mg per 100 g of dry weight and exhibited high antioxidant activity. The highest encapsulation efficiency achieved with the PS, TG, and AG blend was 80.4% for the total carotenoids, and that for the total anthocyanins was 76% with the TG and AG blend. Only one step of antioxidant activity degradation was identified, and the carrier system PSTG was efficient at maintaining the antioxidant activity, with half-life of 23.60-37.27 days. The use of PS alone as a coating material or associated with TG and AG gums resulted in improved retention of bioactive compounds, these being an excellent alternative coating material since they improved the stability of the antioxidant activity of RAP. © 2020 Society of Chemical Industry.

Microencapsulation of Horseradish (Armoracia rusticana L.) Juice Using Spray-Drying.

Horseradish contains many bioactive compounds with antioxidant activity. The current study aimed to evaluate the effect of various wall materials and their ratios on the physical properties and bioactive-compound retention and stability in microencapsulated horseradish leaf and root juices. Horseradish juice was microencapsulated using maltodextrin, maltodextrin/gum Arabic, soy protein isolate, and starch with three different core-to-wall ratios. The total phenolic, total flavonoid, total flavan-3-ol, and total phenolic-acid contents, as well as antioxidant activity, were determined using spectrophotometric methods, whereas individual phenol profiles were determined by high-performance liquid chromatography (HPLC). Multivariate analysis of variance showed that plant material, wall material, and core-to-wall ratio had a significant effect on the bioactive-compound retention and antioxidant-activity preservation. Microcapsules produced from horseradish leaf juice had a significantly higher content of phenolic compounds and antioxidant activity compared to root-juice microcapsules. However, better retention was observed for microencapsulated horseradish root juice. Maltodextrin and maltodextrin/gum Arabic were the most effective wall materials for the retention of bioactive compounds, while they also had a smaller particle size and better solubility. The horseradish-juice microcapsules possess a high content of rutin. The highest stability of bioactive compounds after storage was found at a core-to-wall ratio of 20:80.

Effect of cabinet drying on nutritional quality and drying kinetics of fenugreek leaves (Trigonella foenum-graecum L.)

In the present investigation, fresh fenugreek leaves were blanched in water (80 °C), steam and water added with three chemicals namely potassium metabisulphite (0.5%), magnesium oxide (0.1%) and sodium bicarbonate (0.1%) followed by drying at 40 °C and 50 °C respectively, at 1.1 m/s air velocity in a cabinet dryer. The samples were analyzed for various parameters such as moisture content, moisture ratio, rehydration ratio, ascorbic acid, total chlorophyll and β-carotene content. Among three treated samples, the water added with chemicals blanched samples showed the best result in terms of various quality parameters and maximum nutrient retention after drying at 40 °C. Five mathematical models for thin layer drying were used to predict the drying behavior of the fenugreek leaves. Considering suitable statistical parameters studied for each model, Midilli model showed the best performance and thus applied for this study to predict the drying behavior of fenugreek leaves in above stated conditions. • Blanching and drying of fenugreek leaves was done to reduce the post-harvest losses. • Blanching with chemicals resulted in better retention of bioactive compounds. • Drying at 40 °C led to better product properties as compared to 50 °C. • Midilli model gave best performance to predict drying behavior of fenugreek leaves.

Encapsulation of hot air-dried asian pear powders using rice bran dietary fiber

Asian pear powder (APP) encapsulated using rice bran dietary fiber (RD) and maltodextrin (MD) was investigated for its physical stability, phenolic bioaccessibility, antioxidant activities and major phenolic compounds (arbutin, ferulic acid, p-coumaric acid). Results showed that moisture content, angle of repose, solubility, and color values of APP were all significantly (p < 0.05) affected by addition of RD and MD at various levels. Water adsorption and hygroscopicity were lower in RD/APP mixtures than MD/APP mixture. X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy showed that RD-added APP was more hydrophobic than MD-added APP with significant flowability differences. RD/APP showed higher total and bioaccessible phenolics and antioxidant activities as compared to MD/APP. During storage for 150 days, high retention of bioactive compounds was observed in RD/APP. Therefore, RD improved handling and functional properties of APP as compared to MD.

Retention and stability of bioactive compounds in functional peach beverage using pasteurization, microwave and ultrasound technologies.

The peach functional beverages pasteurized for 10min at 90°C, microwaved for 1.5min at 850W of power and sonicated for 90min at 20kHz of frequency were selected to keep in storage for up to 30days in refrigerator to examine the changes happened to their physicochemical characteristics and functional components. It was observed that the pH and the cloud values of all processed juice samples reduces with the storage time, whereas, the total soluble solids almost remain consistent particularly in microwave and ultrasound treated samples. While storage period causes the decrement in total phenolic content (TPC) and total flavonoid content of treated beverage samples, but ultrasound processing showed greater retention of TPC value up to 5.7% more than other techniques during storage. The similar trend was observed for antioxidant activity where the ultrasound treatment showed improved free radicals (2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activities except ferric ion reducing antioxidant power after 30days of storage.

Insights into effectiveness of tight ultrafiltration and frozen storage in bioactive compound retention in watermelon juice concentrate

AbstractThe aim of this study is to evaluate the potential of tight ultrafiltration for the concentration of bioactive compounds in watermelon juice and also analyze the effectiveness of frozen storage for storing the juice concentrate. The concentration of the juice was performed at two different temperatures of 30 ± 2°C and 23 ± 2°C and at pressures of 2 and 3 bar for concentration factors of 1.5, 2, and 3. Total phenolic content in the concentrate was determined in terms of gallic acid and flavonoid concentration was analyzed in terms of rutin equivalent. Lycopene was determined spectrophotometrically using the hexane extraction method. The ultrafiltration (UF) process was successful in retaining a high percentage of bioactive compounds in the watermelon juice concentrate. Flavonoids showed the highest levels of concentration among the four important bioactive compounds. The ultrafiltration experimental set of T = 23 ± 2°C, P = 3 bar and volumetric concentration factor = 1.5 was found to be most feasible. Frozen storage at −18°C was successful in retaining a high percentage of bioactives in the concentrate after 1 month although vitamin C loss was on the higher side. Lycopene was highly preserved in the concentrate juice after frozen storage with retention of 93%.Practical ApplicationsOne of the major ways to reduce the amount of postharvest losses in watermelon is to convert it to juice by postharvest value addition. To make it available all through the year, the juice has to be processed in order to store it for longer periods. Membrane technology provides the best option to treat the juice in a nonthermal manner to retain its nutritional and sensorial characteristics after processing. Tight ultrafiltration can be a great tool for obtaining a juice concentrate that is rich in bioactive compounds. Watermelon has a significant amount of vitamin C, polyphenols, and also contains lycopene, a carotenoid with potential cancer preventive properties. Tight ultrafiltration can be useful in retaining these important components in the concentrated juice simultaneously reducing the water content, thereby increasing its shelf life. By optimizing different parameters associated with ultrafiltration, it can be possible to industrially scale up this process to make the juice available throughout the year.

Effect of drying methods and storage on bioactive compounds of Moringa oliefera leaf powder

Moringa oleifera (Drumstick tree) is well known for its nutritional quality but usage of leaf powder as a functional ingredient is very less. Hence, the leaves were subjected to hot-air, solar-tunnel and shade drying methods and stored under ambient condition. Solar tunnel drying had 89.58 and 16.66% lesser drying time compared to shade and hot-air drying, respectively. The study showed that solar-tunnel dried leaf powder had high ascorbic acid (471 mg /100g), total carotenoids (2.49 mg/g), total polyphenols (39.29 mg gallic acid equivalent /g) and total chlorophyll (7 mg/g) content compared to other drying methods. Higher retention of bioactive compounds was found in solar-tunnel dried leaf powder during storage. Aerobic plate count was higher in shade dried sample throughout the storage period. It can be concluded from the study that solar-tunnel drying is the best green technology to obtain moringa leaf powder with high retention of bioactive compounds which can be utilized as a functional ingredient in food preparations.

Effects of Different Drying Methods and Temperature on the Drying Behavior and Quality Attributes of Cherry Laurel Fruit

This study aimed to investigate the effect of different drying methods and drying temperature on the drying kinetics, total bioactive compounds, phenolic profile, microstructural properties, rehydration kinetics, and color change of cherry laurel fruit. For this aim, hot air drying (HAD), ultrasound-assisted vacuum drying (USV), and freeze-drying (FD) were conducted on drying of cherry laurel. HAD and USV were conducted at 50, 60, and 70 °C. Drying times of the samples were 1980, 1220, and 770 min for HAD at 50, 60 and 70 °C, and 950, 615, and 445 min at 50, 60, and 70 °C, respectively, for USV. The total bioactive compound was significantly affected by both drying methods and temperature (p &lt; 0.05). FD exhibited the highest total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC), and antioxidant capacity value USV showed a higher amount of bioactive compounds than those of HAD at the same drying temperature. The content of total bioactive compounds significantly increased as the temperature increased for both HAD and USV (p &lt; 0.05). The chlorogenic acid was identified as a major phenolic, and its amount significantly depended on drying methods (p &lt; 0.05). SEM images described the surface characteristic of dried samples. HAD dried products showed higher shrinkage compared to FD and USV. All drying methods significantly affected the total color difference (ΔE) values (p &lt; 0.05). This study proposed that USV could be as an alternative method to HAD due to higher bioactive compounds retention and rehydration ratio, shorter drying time, less color change, and shrinkage formation.

Combined Infrared Freeze Drying and Infrared Drying of Rose-Flavored Yogurt Melts—Effect on Product Quality

This study evaluated the use of infrared freeze drying for different durations in combination with infrared drying (IRFD-IRD) as a means to reduce the drying time and energy consumption without sacrificing the dried product quality during the production of rose-flavored yogurt melts. Total required drying time and energy consumption were examined and compared with those required by IRFD alone. Comparison was also made in terms of physical properties (color, odor, bulk density, hardness, and rehydration time), total phenolic and anthocyanin contents, antioxidant activities, and sensory characteristics of the final products. IRFD-IRD could reduce 11.36–22.73% of the drying time and 9.99–24.87% of the energy consumption in comparison of IRFD alone. IRFD (3 h)-IRD samples had smaller total color difference than that of IRFD samples. Odor, bulk density, and hardness as well as sensory characteristics of IRFD (3 h)-IRD samples were similar to those of IRFD samples. Furthermore, IRFD (3 h)-IRD and IRFD samples possessed similar retention of bioactive compounds as well as antioxidant activities. Combined IRFD (3 h)-IRD is a promising technique for the processing of rose-flavored yogurt melts. The combined drying method significantly reduced the drying time and energy consumption without affecting the final product quality.

Phase separation behavior in zein-gelatin composite film and its modulation effects on retention and release of multiple bioactive compounds

The zein-gelatin (ZG) composite films with customized phase separation structure were fabricated for simultaneous loading and release of tea polyphenol (TP) and oregano essential oil (OEO). The effect of phase separation behavior in ZG films on mechanical and barrier properties was investigated, and retention and release properties of TP and OEO in the selected film were evaluated. Decreasing the mass ratio of zein to gelatin, the morphology of ZG films evolved from the macroscopic phase separation with identified layer boundary (ZG3:1, ZG2:1) to microscopic phase separation with spherical aggregates dispersed in a continuous matrix (ZG1:1, ZG1:2, ZG1:3). The ZG1:2 film, characterized by microscopic phase separation structure with proper mechanical properties, low WVP and one-way moisture barrier property, was selected as an effective carrier for the simultaneous loading of TP and OEO. The ZOGTP film displayed a rough surface morphology caused by TP, and graininess cross-section morphology resulting from the OEO loaded zein aggregates. FTIR results confirmed the existence of hydrogen bond and hydrophobic interactions among TP, OEO and film matrix, respectively. The simultaneous loading led to stronger water barrier property with higher retention rate of TP and OEO in ZG1:2 film. Kinetic analysis suggested the release mechanisms of TP and OEO from ZOGTP film were non-Fick diffusion and were close to the first-order release kinetic. The novel active film with suitable phase separation structure to load and release of multiple bioactive compounds is of particular interest for the design of multifunctional bioactive packaging with tailored structure and performance.

Bioactive properties and oxidative stability of nutmeg oleoresin microencapsulated by freeze drying using native and OSA sorghum starches as wall materials

Microencapsulation is employed to protect bioactive ingredients in foods and is also used for their controlled release at targeted sites. The objectives of this study were to examine the bio active properties and stability of microcapsules containing nutmeg oleoresin encapsulated with different ratios (2:1, 1:1 and 1:2) of gum arabic and sorghum starch (native and OSA modified) prepared by freeze-drying. The properties of nutmeg microcapsules, including oxidation stability, antioxidant activity, total phenolic content and total flavonoid content were evaluated after sixty days storage trial. The finding revealed that freeze drying method had a spectacular effect on the retention of bioactive compounds during storage that consequently improved the storage stability of the all nutmeg encapsulated powders. The sample composed of 1:2 ratio of gum arabic with OSA starch resulted to have lowest peroxide value after 60 days of storage. Furthermore, the microcapsules were also observed through Fourier Transform Infrared spectroscopy and Scanning electron microscopy for advance analysis.

Concentration of bioactive compounds from grape marc using pressurized liquid extraction followed by integrated membrane processes

The integration of pressurized liquid extraction (PLE) with membrane separation technology was used to recover and concentrate monomeric anthocyanins and total phenolics from grape marc. The extracts obtained by PLE were subjected to a preliminary study of stirred dead-end filtration using different commercial flat sheet membranes of nanofiltration (NF). In addition, to reduce membrane fouling and the content of solids in the feed, previous microfiltration (MF) and ultrafiltration (UF) processes were evaluated. The membranes that presented the best performances were selected for cross-flow filtration. The flux of permeate, the retention of bioactive compounds and antioxidant capacity, and the characterization of the membrane surfaces were used to evaluate the performance of the filtration processes. The results obtained in this study suggest that the sequential process based on the previous MF with the MV020 membrane of the grape extract obtained by PLE, followed by the NF step with the NP010 membrane, was the most effective in the concentration of bioactive compounds. The sequential process MV020-NP010 provided excellent results in terms of permeate flux, concentration factor (2.4), retention coefficients of monomeric anthocyanins (78.2%) and total phenolics (71%), and high antioxidant capacity (52%) compared to other tested NF membranes. Fifteen anthocyanins were concentrated in the extracts by UHPLC-UV–Vis. The NP010 membrane had the smallest change in membrane roughness and functional groups after NF. It is concluded that the integration of PLE with the projected sequential process (MV020-NP010) is efficient for the recovery and concentration of bioactive compounds from grape marc, being promising for obtaining functional products with high added value.

Vacuum‐assisted extrusion of red rice ( bao‐dhan ) flour: Physical and phytochemical comparison with conventional extrusion

The effect of vacuum-assisted extrusion cooking on the properties of red rice extrudate was investigated. The rotatable central composite design was employed to determine the effect of independent variables on dependent variables. The process was optimized using an artificial neural network (ANN) and genetic algorithm (GA) The sensitivity analysis of independent variables was conducted and the screw speed showed the highest contribution on the product quality. The optimum condition obtained by ANN and GA was 77.5°C barrel temperature, 32.5% feed moisture, 350 rpm screw speed, and 300 mmHg vacuum level. The developed process was compared with the conventional extrusion process without employing a vacuum in terms of physicochemical and phytochemical properties. The extruded was contented 3.89 mg/L of anthocyanin, 0.021 µm/L of cyanidin-3-glucoside, and 3.21 µm/L of peonidin-3-glucoside. The vacuum-assisted extrusion cooking showed to develop expanded extrudate at low temperatures with higher phytochemical retention. Practical applications Extrusion cooking generally considers as a high-temperature short time process. Due to high temperature and high shear, most of the bioactive compounds are deteriorated during extrusion cooking. Therefore, extruded are considered unhealthy for consumers. The outcome of the present investigation can enhance the retention of bioactive compounds in extruded products. The vacuum-assisted extrusion could expand the extrudate at low temperatures and enhance the retention of bioactive compounds.

The Impact of Maltodextrin and Inulin on the Protection of Natural Antioxidants in Powders Made of Saskatoon Berry Fruit, Juice, and Pomace as Functional Food Ingredients.

The objective of this study was to examine the effect of inulin and maltodextrin applied during vacuum drying of Saskatoon berry fruit, juice, and pomace on the retention of bioactive compounds and antioxidant capacity (radical scavenging capacity (ABTS), ferric reducing antioxidant potential (FRAP)) of powders obtained. Ultra-high performance liquid chromatography (UPLC-PDA-ESI-MS/MS) was used to identify major groups of polyphenolic compounds, such as: flavan-3-ols (35% of all polyphenols for fruit powder, 33% for juice powder, and 39% for pomace powders of all polyphenols), anthocyanins (26% for fruit powder, 5% for juice powder, and 34% for pomace), phenolic acids (33% for fruit powder, 55% for juice powder, and 20% for pomace powder), and flavanols (6% for fruit powder, 6% for juice powder, and 7% for pomace powder). In general, the content of polyphenols was more dependent on the content than on the type of carrier used for drying, regardless of the matrix tested. The average sum of polyphenols and the antioxidant activity (for ABTS and FRAP assay) of the powders with 30% of carrier addition were 5054.2 mg/100 g dry matter (d.m.) as well as 5.3 and 3.6 mmol Trolox/100 g d.m. in the ABTS and FRAP tests, respectively. The increase in carrier concentration by 20% caused a decrease of 1.5-fold in the content of polyphenols and a 1.6-fold and 1.5-fold in the antioxidant potential, regardless of the matrix tested. The principal component analysis (PCA) analysis indicated that the freeze-drying process led to the lowest degradation of the identified compounds, regardless of the matrix tested, with the exception of juice and pomace powders dried by vacuum drying at 60 °C. In this case, the release of (−)-epicatechin was observed, causing an increase in the flavanol contents. Thus, this work demonstrated the effect of processing and matrix composition on the preservation of antioxidant bioactives in Saskatoon berry powders. Properly designed high-quality Saskatoon berry powders with the mentioned carriers may be used as nutraceutical additives to fortify food products and to improve their functional properties.

Antioxidant and antimicrobial properties of organic fruits subjected to PEF-assisted osmotic dehydration

The effect of PEF pre-treatment prior to osmotic dehydration on mass transfer parameters, colour, antioxidant and antimicrobial properties in organic strawberries and kiwifruits was evaluated. An increase of water loss in both fruits upon the application of combined processes was noticed (up to 21.6%), while a decrease of solid gain was observed only in kiwifruit samples dehydrated in sucrose (about 45%). In general, the combined treatments were beneficial for colour maintenance in both fruit tissues. The antioxidant capacity (DPPH) and activity (ORAC) increased after PEF treatment, however, all the combined treatments reduced significantly these values (of about 20 and 28% for strawberry and of about 56 and 35% for kiwifruit, respectively for DPPH and ORAC methods). In general, PEF treatment alone was also effective with regard to an increase in the antimicrobial activity of the samples against the tested microorganisms (B. subtilis, E.coli, S. cerevisiae). Industrial relevancePEF pre-treatment coupled with osmotic dehydration could be applied at industrial level to obtain semi-dried fruit products. Moreover, both processes could be used as pre-treatments for drying process, in order to develop healthy and microbiologically stable fruit snacks. In fact, in the present work we observed that PEF pre-treatment alone promoted higher antioxidant and antimicrobial activity. The combined process decreased both parameters, suggesting that an accurate study is necessary to evaluate the benefits of these processes in terms of bioactive compounds retention and time and energy consumption in further drying process. The results of the present study could be used as a starting point for the industries to design novel products with intermediate moisture content intended for further processing.

Effect of Different Methods of Thermal Treatment on Starch and Bioactive Compounds of Potato

The study examined the effects of various methods of thermal treatment of Lord cultivar potato tubers on changes in starch, polyphenols, vitamin C, antioxidant activity, and mineral compounds. Following heat treatment in order to determine further transformations of starch, the potatoes were stored at 2 °C/24 h. Changes in starch, bioactive compounds and antioxidant properties varied depending on the treatment method. In general, higher retention of bioactive compounds was noted for tubers treated with “dry” methods, such as microwaving or grilling than for tubers treated with “wet” methods, e.g., boiling in water, steam cooking or cooking in a combi oven. These samples were also characterised by a higher resistant starch content. Cold storage resulted in an increase in the proportion of resistant starch. Total phenols content ranged from 210.96 (boiling) to 348.46 mg/100 g DW (grilling) and vitamin C content ranged from 43.79 (boiling) to 68.83 mg/100 g DW (microwaving). DPPH radical scavenging activity was the highest for the grilled tubers. The results indicate microwaving and grilling as the most favourable thermal treatments of potato.

Pasteurization of passion fruit Passiflora setacea pulp to optimize bioactive compounds retention

Passiflora setacea is a wild species of passion fruit with interesting functional properties. Fruit seasonality demands conservation methods to enable its consumption throughout the year. We evaluated High Temperature Short Time (HTST) and Low Temperature Long Time (LTLT) binomials on physical, chemical, antioxidant and sensory characteristics of Passiflora setacea pulps. In natura (IN) and pasteurized pulps were analysed for DPPH, FRAP, ORAC, total phenolic content (TPC), vitamin C, bioactive amines, flavonoids, color, remaining enzymatic activity (REA), microbiological analyzes, sensory evaluation and physical stability. All binomials reached microbiological standards. Binomials 82 °C/20 s and 82 °C/40 s were selected for providing higher total antioxidant activity (TAA), TPC and lower REA. The highest levels of antioxidant activity, flavonoids, vitamin C were kept by 82 °C/20 s, without difference from IN pulp. LTLT binomial showed higher retention of bioactive amines, but also higher REA. Sensory acceptance was not affected by the binomials but pasteurized-cooked flavor was more checked for 82 °C 40 s than IN pulp.