Retention Of Bioactive Compounds Research Articles

Kinetics of cashew apple drying through mechanistic models and analysis of the effects of drying conditions on the retention of bioactive compounds

AbstractGlobal cashew nut production is nearly 4 million tons per year, valued at 7 billion US dollars. Remarkably, almost the entire cashew apple crop, amounting to 20 million tons annually, goes to waste. However, the cashew apple contains valuable nutraceutical compounds, including tannins, polyphenols, and carotenoids, estimated to be worth 150 million US dollars annually. Due to the highly perishable nature of cashew apples, degradation is a significant issue. In response, the current work has established drying as an effective preservation technique for these bioactive components. The effect of drying temperature on bioactive compounds has been thoroughly investigated. The non‐random two liquid (NRTL) activity coefficient model effectively captures the thermodynamics of the drying process. To facilitate the selection and design of drying equipment, two mechanistic mass transfer models were developed. The first model employs the Maxwell‐Stefan framework to account for internal diffusion, with external mass transfer resistance appearing as a boundary condition. While this model works well for products like grapes, it proved inadequate for explaining the drying behaviour of cashew apples. Consequently, a second model was developed, postulating rapid moisture transport by capillary action within the cashew apple. This model effectively captures the effects of a wide range of operating conditions, using only external mass transfer resistance as the tuneable kinetic parameter. This mechanistic model is more suitable for dryer design compared to conventional phenomenological models like the logarithmic model and the two‐term exponential model.

Sequential Pulsed Light and Ultrasound Treatments for the Inactivation of Saccharomyces cerevisiae and PPO and the Retention of Bioactive Compounds in Sweet Lime Juice.

Designing a pasteurization con dition for sweet lime juice while ensuring microbial safety, enzymatic stability, and high nutritional quality is crucial for satisfying stakeholder demands. The present research investigates the effects of matrix pH, ultrasound treatments, and sequential pulsed light on the microbial population, enzyme activity, and bioactive chemicals in sweet lime juice. The sequential pulsed light (PL: 0.6-0.84 J/cm2) and ultrasound (US: 0.2-0.4 W/cm3) treatments for sweet lime juice were optimized using response surface methodology (RSM). A three-factor full factorial design was used for this purpose. The independent variables encompassed pH (X1), PL effective fluence (X2, J/cm2), and US intensity (X3, W/cm3). The responses assessed included the inactivation of Saccharomyces cerevisiae (Y1, log cfu/mL) and polyphenol oxidase (PPO: Y2 in %) and the retention of vitamin C (Y3, %). The polynomial models were optimized using numerical optimization to attain the maximum desirability value (0.89). The optimized PL + US sample (0.8 J/cm2 + 0.4 W/cm3, respectively) at pH 3.5 resulted in a 5-log cycle reduction in S. cerevisiae count and a 90% inactivation in PPO activity and retained 95% of its vitamin C content. This optimized sample underwent further analysis, including phenolic profiling, assessment of microbial cell morphology, and examination of enzyme conformational changes. After sequential pulsed-light (0.8 J/cm2) and ultrasound (0.4 W/cm3) treatments, yeast cells showed unusual structural changes, indicating additional targets besides membranes. Following PL + US treatment, the PPO composition changed to 2.7 ± 0.1% α-helix, 33.9 ± 0.3% β-sheet, 1.4 ± 0.2% β-turn, and 62 ± 0.7% random coil. Impressively, the optimized PL + US sample maintained a sensory acceptance level similar to that of the untreated sample.

Effect of novel blanching methods on Infra-red drying characteristics and quality attributes of elephant foot yam

The present study evaluated the effect of various pre-treatments (Potassium metabisulphite (KMS), KMS+Ultrasonication (KMSUS), KMS+Microwave (KMSMW), KMS+Hot water (KMSHWB) followed by infrared drying on the quality of Elephant Foot Yam (EFY). KMSMW-treated samples showed the fastest drying rate and highest moisture diffusivity, whereas the KMS-treated sample had the highest weight gain (171.57 %) in rehydration (80 °C). KMSMW and KMSHWB-treated samples exhibited softer textures in rehydration compared to control. Pre-treated samples had higher water absorption capacity and lower oil absorption capacity compared to the control. Pre-treatments also influenced the amylose content and the highest amylose content was observed for KMSUS (21.25 %). Pre-treatments positively influenced the retention of bioactive compounds and reduced the calcium oxalate (117.37 mg/g to 64.09 mg/g). Among all the pre-treatments, KMSHWB showed higher retention of bioactive compounds viz., TPC (297.67 mg GAE/100 g), TFC (922.22 mg QE/100 g), DPPH scavenging activity (57.91 %), ABTS (1.42 mmol TE/100 g) and lowest calcium oxalate (64.09 mg/100 g).

A comparative assessment of drying kinetics, energy consumption, mathematical modeling, and multivariate analysis of Indian borage (Plectranthus amboinicus) leaves

AbstractIn the current study, four drying methods, namely microwave (MD), vacuum (VD), hot air (HAD), and freeze drying (FD), were compared for drying of Indian borage (Plectranthus amboinicus) leaves for optimum energy consumption and bioactive compounds' retention. Effective moisture diffusivity for MD was about 100 times more than that of HAD and VD. MD at 600 W showed minimum specific energy consumption (4.04 kWh/kg), proving the most suitable drying condition. Moreover, it showed desirable energy values in terms of maximum specific moisture extraction rate (0.265 kg moisture/kWh) and maximum drying efficiency (15.85%). Bioactive compounds' retention in terms of phenols, antioxidants, and flavonoids was better in MD, followed by FD. Mathematical modeling of drying kinetics data revealed proper fitting of three drying models, namely, Aghbashlo, Modified Page‐II, and Page model, for explaining the drying behavior of Indian borage leaves. Multivariate characterization using principal component analysis revealed that FD and MD had a strong effect on bioactive compounds' retention, while VD and HAD showed least effect. Hence, based on optimum energy utilization and bioactive compounds' retention, MD at 600 W was selected for efficient drying of Indian borage leaves.Practical applicationsDrying of Indian borage leaves using microwave drying (MD) resulted in quicker drying with retention of bioactive compounds and color of dried leaves. The energy aspects were also favorable for industrial scale‐up. With due consideration to capacity enhancement in MD, it can prove to be a promising source of drying for culinary, medicinal, and aromatic plants.

Enhancing litchi shelf life with gluten-based nanocomposite films: A comparative study of montmorillonite and starch nanocrystals reinforced with chitosan

This study investigates the efficacy of gluten films incorporated with montmorillonite (MMT) and starch nanocrystals (SNCs), further enriched with chitosan, in preserving the quality of litchis over a 20-day storage period at 4 °C. The addition of MMT/SNCs along with chitosan boosts the tensile strength (52.44 to 57.00 MPa) and surface uniformity of the films while also decreasing water vapour transmission rates (0.77 to 0.68 × 10−3 g/m2/h). Notably, litchis wrapped in these nanocomposite films demonstrate superior shelf stability compared to untreated litchis, which undergo considerable deterioration. Among the film variants, SNCs/chitosan films (GSL2) outperform MMT/chitosan (GML2) due to their superior barrier properties. By the 20th day of storage, litchis packaged in GSL2 films display reduced antioxidant enzyme activity (polyphenol oxidase: 3.18 to 8.08 unit/min/g fruit weight; peroxidase: 0.94 to 5.29 unit/min/g fruit weight) and higher retention of bioactive compounds, including anthocyanin (9.15 to 9.90 mg/100 g), phenolics (347.7 to 362.07 mg/100 g), and ascorbic acid (28.21 to 29.09 mg/100 g) in litchi pericarps during last intervals. Similarly, less alteration was observed in the firmness (8.47 % and 7.36 %) and weight loss (24.04 % and 19.86 %) of the litchis packaged in GML2 and GSL2, respectively as compared to unpackaged litchis. Notably, litchi pericarp exhibits negligible functional group changes when packed in GML2 and GSL2 films until the 15th day of storage. In summary, GML2 and GSL2 films effectively maintain acceptable litchi quality for three weeks.

Melatonin treatment enhances bioactive compound retention, antioxidant activity and shelf‐life of bell pepper (Capsicum annuum L.) during cold storage

SummaryMelatonin (MT), a natural signalling compound derived from tryptophan, has gained significant attention for delaying postharvest ripening and senescence in various fruits and vegetables. In the present study, the effect of MT treatment was evaluated on the postharvest shelf‐life of bell pepper. Fruits were dipped in various MT concentrations (70, 120, 170, 220 μmol L−1) for 20 min and stored at 10 ± 1 °C for 20 days. The bell pepper treated with 120 μmol L−1 MT significantly suppressed respiration, weight loss and delayed chlorophyll degradation. Additionally, MT (120 μmol L−1) treatment reduced loss of firmness, titratable acidity and retained total phenol, flavonoid and ascorbic acid content. It hindered malondialdehyde accumulation by enhanced DPPH radical scavenging and antioxidant enzyme activity like superoxide dismutase, catalase and peroxidase, over the control. Conclusively, 120 μmol L−1 MT prolongs the postharvest shelf‐life of bell pepper by 20 days with superior sensory quality, surpassing the control by 10 days. Therefore, MT treatment is a commercially useful technology for maintaining quality and prolonging the postharvest shelf‐life of bell pepper.

Effect of thermal treatment on selected bioactive compounds and physicochemical properties of a blackberry-soy-flaxseed beverage

Three prototypes of a blackberry-soy-flaxseed beverage were formulated and processed by pasteurization (71.1 °C, 3 s) or commercial sterilization (heating to 87 °C followed by immediate hot-fill). The effects of heat exposure on selected bioactive compounds (total phenolics, ellagitannins, anthocyanins, isoflavones and lignans) and physicochemical properties (pH, °Brix, turbidity, viscosity and color) were evaluated. Bioactive compounds were quantified by HPLC-DAD analytical methods. No significant changes (p > 0.05) were observed in the contents of total phenolic compounds, ellagitannins, cyanidin-3-glucoside, isoflavones (daidzein and genistein), or lignans, regardless of the heat regime applied or the beverage formulation. The pH and soluble solids were similar among the three beverages and did not change after heat treatments. The content of cyanidin-3-malonyl-glucoside, a polyphenol, significantly decreased (p < 0.05) by 35–45% with the hot-fill process in all beverage prototypes. Turbidity was not significantly affected by the type of heat treatment, but the viscosity of the hot-filled beverages was significantly higher (p < 0.05) than that of the pasteurized and non-pasteurized prototypes. No significant differences (p < 0.05) in color parameters L*, a*, and b* were observed. Total color difference (DE*) values indicated differences in perceivable color among samples of the same beverage exposed to the heat processing regimes. DE* values for prototype 1 processed by pasteurization and commercial sterilization were distinct from non-pasteurized beverage. DE* values for prototypes 2 and 3 processed by pasteurization were distinct from those of the non-pasteurized beverage. Pasteurization allowed higher retention of bioactive compounds and had a lower impact on the physicochemical properties of the blackberry-soy-flaxseed beverage.

Influence of ultrasonic-assisted osmotic dehydration pretreatment on hot air-assisted radio frequency drying of bitter gourd

Bitter gourd is a versatile vegetable that brings health-promoting benefits to consumers. To maintain its high nutrition values and ensure year-round availability, proper post-harvest processes are essential for preserving its original properties. However, there is limited knowledge regarding how pretreatment methods impact the physicochemical properties of pretreated bitter gourd and the performance of subsequent hot air-assisted radio frequency drying (HARFD) process. In the present study, bitter gourd underwent osmotic dehydration (OD) and ultrasonic-assisted osmotic dehydration (UAOD) pretreatment with different ultrasound power levels (400, 800, and 1200 W). The physicochemical properties of the pretreated samples, such as mass transfer behavior, water migration status, dielectric loss factor, and others, were compared. The drying duration, energy consumption, and various quality attributes (e.g., color index, rehydration, nutritional compositions, antioxidant activity, etc.) of the HARFD dried products were also examined. The microstructure observations demonstrated that acoustic waves induced the structural changes and created microchannels. Additionally, physicochemical properties of the pretreated samples showed that OD and UAOD methods significantly facilitated water migration status and increased the dielectric loss factor. Compared to control and OD methods, three UAOD methods successfully reduced the drying duration by 7.9%–30.3% and total energy consumption by 5.8%–28.3% for the entire processing steps. Furthermore, UAOD methods improved the total phenolic content, total chlorophyll retention, DPPH and ABTS values of dried bitter gourds by 32.3%–36.7%, 12.6%–20.3%, 23.4%–31.6%, and 20.7%–26.3%, respectively, compared to the control methods. Overall, UAOD-400 W samples after drying exhibited improved quality characteristics, including reduced color difference, increased retention of bioactive compounds, higher rehydration ratio, and enhanced antioxidant capacity. This study underscores the effectiveness of UAOD application in improving both processing efficiency and quality of bitter gourds produced by HARFD.

Impact of pulsed electric fields on membrane disintegration, drying, and osmotic dehydration of foods

AbstractDrying is one of the oldest and most conventional methods used to preserve foods. Unique traditional methods have been applied for the drying of plant‐based food products. However, the disadvantage of this approach is the low drying rate, high energy, and processing costs accompanied by the loss of nutritional quality in food products. As a substitute, pulsed electric field (PEF) is a modern and promising technique that has various advantages over thermal treatments. Nowadays, it has become an area of innovation to meet increasing industrial demands. Application of PEF during drying and osmotic dehydration has beneficial impacts on the extension of shelf‐life, increases in storage stability, and improvement of nutritional quality. Upscaling the use of PEF from laboratory to industrial scale while maintaining productivity is an area for further research and development. The aim of this commentary review is to give an overview of a newly proposed PEF process, which improves drying rate, mass‐energy transfer, retention of bioactive compounds, and osmotic dehydration in food. PEF processing led to achieving the innovative development of a wide range of foods and was extended to solve environmental issues. Drying food products is the most promising area in the food industry which needs improvement in terms of achieving energy efficiency and cost‐effectiveness to dry food products with the maintenance of nutritional properties to adequate levels. In this regard, PEF could be a suitable and novel drying method to overcome the limitations of conventional drying methods which might open new horizons for valuable research in manufacturing dried fruits and vegetables on an industrial scale.

Spray dried powder of common fruit juices: Enhancement of main properties

Low retention of bioactive compounds caused by high stickiness associated with sugar-rich fluids are of concern in the industrial production of spray-dried fruit powders. An alternative is spray-freeze-drying SFD, which operates under low temperatures but subsequent handling can be impacted by high hygroscopicity. This study explores the use of bulking (maltose and maltodextrin) and wall materials (hydroxypropyl methylcellulose HPMC and whey protein) to encapsulate strawberry, mango, and orange juices. SFD showed the highest spraying yields, on average 85%. Stickiness showed significant changes (p < 0.05) among encapsulated and non-encapsulated powders. HPMC encapsulation improved SFD fruit powder by lower moisture uptake (on average 2%). Encapsulation obtained by whey protein and by HPMC resulted in the lowest adhesion forces between powders, around 40 g, and in the lowest mold spore count, 25 per area, in powders exposed at room temperature for two months.

Influence of various cooking treatments and extraction solvents on bioactive compounds and antioxidant capacities of bottle gourd (Lagenaria siceraria) fruit in India

Bottle gourd is a good source of health-beneficial bioactive substances. This research aimed at evaluating the effect of different cooking methods (pressure cooking, microwaving, and frying) and extraction solvents (methanol, ethanol and butanol) on bottle gourd fruit phenolic compounds and antioxidant capacity. The quantitative estimation of polyphenolic compounds, flavonoids and tannins was estimated by spectrophotometric methods. The antioxidative properties were evaluated using ferric thiocyanate (FTC), thiobarbituric acid (TBA), ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests using the standard methods. Moreover, quantification of individual polyphenols was carried out by high-performance thin layer chromatography (HPTLC) technique. Frying and pressure-cooking thermal treatments were observed to be the best methods for retaining bioactive molecules. When compared to the raw counterpart, the retention level of total phenol content (TPC) in pressure cooked and fried samples was 23.8% and 13.3%, respectively. Similarly, antioxidant capacity in terms of FRAP was observed to increase by 47.26% after pressure cooking and 28.50% after microwave cooking in respect to the raw sample. The HPTLC results showed that this fruit has high antioxidant capacity and is rich in phenolic acid [gallic(17.83 mg g−1dwb), p-coumaric (6.70 mg g−1dwb)and vanillic (60.66 mg g−1dwb] and flavonoids [quercetin (24.64 mg g−1dwb) and myrecetin (20.73 mg g−1dwb].The chromatography indicated destruction and transformation of new phenolic compounds due to heat treatments. The correlation analysis revealed that flavonoids were much more responsible for their antioxidant activity. Cooking methods and extraction solvents affected the retention and recovery of polyphenolic compounds available in bottle gourd fruit. These findings offer valuable information for optimizing cooking techniques to preserve and enhance the nutritional and antioxidant properties of bottle gourd, making it a valuable fruit for a healthy diet. Pressure cooking could be the most suitable cooking treatment as far as retention of bioactive compounds like phenolic acids is concerned.Graphical

Enzyme activity and nutritional profile of different-sized carrot cubes treated with supercritical carbon dioxide

This study evaluated changes in the enzyme activity, color, carotenoids, sugar profile, individual phenolic compounds, and antioxidant capacity of supercritical carbon dioxide (SCCD)-treated carrot cubes of different sizes (1 cm and 2 cm). Results demonstrated that SCCD reduced the activities of polyphenol oxidase (PPO) and peroxidase (POD) more in 1 cm carrot cubes than in 2 cm carrot cubes. Nevertheless, the a* , b* , and ∆E values of 1 cm SCCD-treated were enhanced compared to 2 cm SCCD-treated samples. The carotenoids, phenolic compounds, and antioxidant capacity of 1 cm SCCD-treated samples were increased under moderate processing conditions. In contrast, the nutritional composition in 1 cm SCCD-treated samples was lower than in 2 cm SCCD-treated samples at harsh processing conditions. The principal component and correction analysis displayed a visual variation between the enzyme activities and nutritional composition of 1 cm and 2 cm carrot cubes after SCCD processing. According to the results above, 1 cm carrot cubes processed with SCCD at 10 MPa, 35 ℃, and 45 min are the most effective at preserving fresh-cut carrots with relatively high enzyme inactivation and the highest retention of bioactive compounds. This work provides a more comprehensive theoretical basis for optimizing SCCD processing for fresh-cut carrots and recommendations for industrial production.

Improving microfiltration efficiency of fruit beverages through backpulsing: Impact on permeate flux, cost-effectiveness and bioactive compounds retention

ABSTRACT Cross-flow microfiltration (CFM) combined with ultra-clean or aseptic packaging offers a promising solution to meet consumer demand for more natural, non-heat treated ready-to-drink fruit beverages. However, membrane fouling can significantly reduce the efficiency of CFM and increase the production cost. To address this issue, we studied the effect of backpulsing on the performance of a semi-industrial CFM equipment featuring 2 m2 of ceramic membranes with 0.2 μm pore size. Using an optimum transmembrane pressure of 150 kPa, we found that backpulsing with a high frequency (every minute) at the beginning of microfiltration and then slowing down the frequency (every 2 min) resulted in higher (+14%) and more consistent average fluxes (100 l.h−1.m−2) while reaching volumetric concentration ratio up to 11. Additionally, the overall specific energy requirements are reduced by 12.5% to 0.0376 kWh.l-1 of treated juice, which is the lowest value among all known de-bacterizing processes, including thermal pasteurization. Importantly, our results showed that backpulsing reduces the retention of the main bioactive compounds of blackberry, including anthocyanins and ellagitannins. These findings demonstrate that CFM with backpulsing is a more cost-effective process that allows for the production of stabilized fruit juices with higher content of bioactive compounds.

Development, characterization, and immunomodulation performance of spray-dried Moringa oleifera seed extract in Longfin yellowtail Seriola rivoliana.

Moringa oleifera is one of the most promising plants in aquaculture because it improves the health status, zootechnical parameters and resistance against diseases. This research evaluates the physicochemical, antioxidant values of spray-dried Moringa oleifera seed extract microencapsulates obtained at 140 and 180°C with whey protein concentrate (WPC) and maltodextrin (MD) as wall materials in two different proportions: WPC 100% and WPC-MD (3:1). Also, immune response of peripheral blood leukocytes (PBL) of Longfin yellowtail Seriola rivoliana stimulated with spray-dried Moringa oleifera seed for 24h was assessed. The physicochemical parameters show that the recovery yield for all the treatments was of 65% and microencapsulates demonstrated to be stable in the physicochemical tests with low solubilization times and protection against humidity. For WPC-MD (3:1)/140°C, bioactive compound retention and antioxidant potential were higher than in other combinations. The immunological test show that any treatments was non-cytotoxic against peripheral blood leukocytes. WPC-MD (3:1)/140°C treatment enhanced immune parameters as phagocytosis, respiratory burst, myeloperoxidase activities and nitric oxide production. Immune related genes as IL-1β and TNF-α were up-regulated in those stimulated leukocytes with WPC-MD (3:1)/140°C. The results suggest that this combination may be a good alternative for animal health as a medicinal and immunostimulant additive.

RSM and ANN approach for optimization of ultrasonic assisted extraction of pumpkin seed oil and their quality assessment

The current study focuses on optimization of process parameters for ultrasonic assisted extraction (UAE) of pumpkin seed oil (PSO) using response surface methodology (RSM) and artificial neural network (ANN). Three parameters of UAE process, amplitude, time and solvent to seed (S:S) ratio were selected in the range of 20–40 %, 15–45 min and 2–6 mL/g respectively and optimized on the basis of responses viz. yield, total phenolic compounds (TPC), squalene content and induction time of oil. The optimum process conditions of UAE were obtained as amplitude- 34.76 %, time- 34.37 min and the S:S ratio 6 mL/g. Under these optimum conditions, the oil showed good yield 39.05 %, TPC 45.02 mg GAE/g, squalene content 447.4 mg/100 g and induction time 5.27 h. The ANN model was developed using multilayer perceptron (MLP) and trained with back propagation algorithm utilizing training data set. The results indicate that the predicted values of responses by ANN model were in good agreement with the experimental values than the RSM model. The UAE-PSO showed better retention of bioactive compounds along with far better oil stability as compared to SE-PSO. The Scanning electron microscopy (SEM) analysis showed the random porous pores and rupture cell wall matrix in UAE treated seed powder.

Sensory, physicochemical, and functional stability of freeze-dried blackcurrant (Ribes nigrum L.) Snacks. Effect of sweeteners.

The objective of this work was to develop two freeze-dried snacks from blackcurrant and different sweeteners: honey/isomalt (HI) sweetened with honey/isomalt, and isomalt/stevia (IS) sweetened with isomalt/stevia. Both snacks showed high bioactive compounds retention (>75%) and no significant changes in several physicochemical properties after 6 months storage. Fresh snacks were hard and crunchy, and the perception of consumers within liking categories was: HI: 43%, and IS: 72%. After storage HI snack showed higher acceptance by consumers (75% within liking categories) while IS snack showed a decrease in their acceptance (63% within disliking categories). The penalty analysis showed that the sensory shelf-life of both snacks would be limited by the changes produced in texture and color during storage. HI snack could reach six storage months, while IS would be stored up to 3 months. The use of diverse sweeteners allowed obtaining two different products which could be incorporated into a healthy diet.

Effect of osmodehydration on the quality attributes of plum (Prunus domestica)

Plum (Prunus domestica) is a seasonal nutraceutical fruit rich in many functional food nutrients such as vitamin C, antioxidants, total phenolic content, and minerals. Recently, researchers have focused on improvised technologies for the retention of bioactive compounds during the processing of perishable fruits; plum is one of these fruits. This study looked at how the percentage of moisture content and percentage of acidity were affected by conventional drying and osmotic dehydration. Total phenolic content (mg GA/100 g of plum), total anthocyanin content (mg/100 g), and vitamin C (mg/100 g) Conventional drying of fruit was carried out at 80.0 ℃ for 5 h. At various temperatures (45.0 ℃, 50.0 ℃, and 55.0 ℃) and hypertonic solution concentrations (65.0 B, 70.0 B, and 75.0 B), the whole fruit was osmotically dehydrated. It was observed that the osmotically treated fruit retains more nutrients than conventionally dried fruit. The total phenolic content of fruit significantly increased with the increase in process temperature. However, vitamin C and total anthocyanin content of the fruit decreased significantly with process temperature, and hypertonic solution concentration was observed. Hence, it was concluded that osmodehydration could be employed for nutrient retention in plum fruit over conventional drying. This process needs to be further refined, improvised, and optimised for plum processing.

Investigating the Influence of Drying Temperature and Tray Loads on Kinetics, Moisture Diffusivity, Retention of Bioactive Compounds, and Color Characteristics of Baby Corn

Investigating the Influence of Drying Temperature and Tray Loads on Kinetics, Moisture Diffusivity, Retention of Bioactive Compounds, and Color Characteristics of Baby Corn

Nutritionally enhanced milk protein and starch-based extrudates made from agro-food byproducts using supercritical fluid extrusion

This study aimed to develop nutritionally enhanced snacks through the synergistic combination of two diverse nutrient sources: milk protein concentrate containing >81% milk protein (MPC81), and a composite source of fiber (>70 wt%) and bioactive compounds (total phenolics, flavonoids, antioxidants, and vitamin C) in the form of agro-industrial byproducts such as apple pomace. Starch and MPC81-based formulations containing 30% (w/w) apple pomace powder were extruded into puffs using supercritical fluid extrusion (SCFX). The effect of SCFX on the retention of bioactive compounds along with the physical, textural, and morphological properties of starch and protein-based extrudates were investigated and compared. Additionally, changes in inter-and intra-molecular interactions among biopolymers during extrusion, and their role in the expansion characteristics of extrudates were also quantified. The resulting MPC81-based extrudates were found to have lighter (0.12 g/cm3 piece density) and softer texture (3.16 kg hardness) compared to starch-based extrudates (0.23 g/cm3 piece density, 12.06 kg hardness), indicating that MPC81-based extrudates containing 30% apple pomace powder offer better functional and sensory-related physical properties. Because of low-temperature (∼25 °C barrel temperature, ∼85 °C product temperature), and low-shear (100 rpm screw speed) along with the use of SC-CO2 as a blowing agent, the resulting extrudates were observed to retain up to 80% total phenolics, 75% antioxidants and 62% vitamin C, which are significantly higher than those reported previously using high-temperature, steam-based cooking extrusion. The FTIR spectra of starch-based formulations indicated a loss of crystallinity and decreased cellulose-lignin interactions, which contributed to the improved extrudate expansion. On the other hand, the expanded protein network was presumably stabilized by an increase in protein aggregation, mainly composed of an elevated β-structure, as confirmed by the FTIR analysis of the protein-based extrudates. The nutritional profile showed that milk protein-based puffs were nutritionally far superior, having significantly higher levels of protein, ash, and fat, as compared to the starch-based puffs. Overall, this study highlights the potential of SCFX to produce milk protein-based extruded products that are nutritionally enriched with agro-industry byproducts such as fruit and vegetable pomace, thereby, adding value to the industrial byproducts streams and lowering the cost of more expensive protein-based products.

Evaluation of Drying Temperature on Bioactive Compounds Retention in Pasta Enriched with Chlorella Luteroviridis Biomass

Microalga incorporation in pasta is an interesting alternative to enrich human diet with important nutrients. However, if present in high amounts, it can weaken the protein network, resulting in a low-quality pasta, with poor texture properties and high cooking loss. This study verified the effect of drying temperature on technological proprieties and carotenoids retention in pasta enriched with 2 % of Chlorella biomass powder. Two drying conditions, high temperature (75-80 °C and 75 % HR), and low temperature (50 °C and 81 % HR) were tested. Pasta samples were analyzed before and after the cooking process and compared to a control sample (not dried). Cooking properties, color, total carotenoids content and carotenoids identification and quantification were evaluated. The high drying temperature resulted in a pasta with lower cooking loss and higher carotenoids content. The drying process increased the nutrients bio-accessibility and promoted a stronger and denser protein network.