Using a combined neural network ─ genetic algorithm approach for predicting the complex rheological characteristics of microfluidized sugarcane juice

Periodic Flows in Microfluidics

Microfluidics, the science and technology of manipulating fluids in microscale channels, offers numerous advantages, such as low energy consumption, compact device size, precise control, fast reaction, and enhanced portability. These benefits have led to applications in biomedical assays, disease diagnostics, drug discovery, neuroscience, and so on. Fluid flow within microfluidic channels is typically in the laminar flow region, which is characterized by low Reynolds numbers but brings the challenge of efficient mixing of fluids. Periodic flows are time-dependent fluid flows, featuring repetitive patterns that can significantly improve fluid mixing and extend the effective length of microchannels for submicron and nanoparticle manipulation. Besides, periodic flow is crucial in organ-on-a-chip (OoC) for accurately modeling physiological processes, advancing disease understanding, drug development, and personalized medicine. Various techniques for generating periodic flows have been reported, including syringe pumps, peristalsis, and actuation based on electric, magnetic, acoustic, mechanical, pneumatic, and fluidic forces, yet comprehensive reviews on this topic remain limited. This paper aims to provide a comprehensive review of periodic flows in microfluidics, from fundamental mechanisms to generation techniques and applications. The challenges and future perspectives are also discussed to exploit the potential of periodic flows in microfluidics.

Artificial neural networks (ANN)-genetic algorithm (GA) optimization on thermosonicated achocha juice: kinetic and thermodynamic perspectives of retained phytocompounds

The extraction of phytocompounds from Achocha (Cyclanthera pedata) vegetable juice using traditional methods often results in suboptimal yields and efficiency. This study aimed to enhance the extraction process through the application of thermosonication (TS). To achieve this, an artificial neural network (ANN) and a genetic algorithm (GA) were utilized to simulate and optimize the process parameters. The study investigated the influence of ultrasonic amplitude (30%-50%), temperature (30 °C-50 °C), and sonication duration (15-60 min) on total polyphenolic content (TPC), total flavonoid content (TFC), antioxidant activity (AOA), and ascorbic acid content (AA). Remarkably, the ANN-GA optimization resulted in optimal TS conditions: an ultrasonic amplitude of 40%, a temperature of 40 °C, and a sonication duration of 30 min. Subsequent analysis of extraction kinetics and thermodynamics across various temperatures (30 °C-50 °C) and extraction times (0-30 min) demonstrated R2 (0.98821) and χ2 (1.74773) for TPC with activation energy (Ea) 26.0456, R2 (0.99906) and χ2 (0.07215) for TFC with Ea 26.2336, R2 (0.99867) and χ2 (0.03003) for AOA with Ea 26.0987, R2 (0.99731) and χ2 (0.13719) for AA with Ea 26.0984, validating the pseudo second-order kinetic model. These findings indicate that increased temperature enhances the saturation concentration and rate constant of phytochemical extraction.

Effect of microfluidization on quality characteristics of sapodilla (Manilkara achras L.) juice

Various oxidative enzymes account for the quality degradation of sapodilla (Manilkara achras L.) juice and need to be inactivated through emerging and continuous green pressure processing technology. In this study, pressurization of sapodilla juice was attempted via microfluidization (MF) at pressure range of 10,000-30,000 pound per square inch (psi) with 1-3 passes or cycles. The impact of microfluidization on the activity of polyphenol oxidase (PPO), peroxidase (POD), color, total soluble solid (TSS), viscosity, serum cloudiness along with particle size, and microbial load of sapodilla juice was assessed. Results showed that microfluidization (MF) decreased the residual PPO activity from 100 to 80.78 % and POD activity from 100 to 40.57%. However, TSS (18.81-19.01 %), viscosity (2.64-2.06 cP), serum cloudiness (2.19-1.22 %) and total color change (3.19-18.54) was also significantly affected. Most of these changes were observed due to particle size (PS) reduction that varied from 65.19 to 8.13 μm. Microfluidized juice revealed color improvement at particular MF pressure and pass due to enzyme inactivation. Moreover, lowest microbial load (2.89 Log CFU/ mL) was found at 30,000 psi/3 pass of MF as compared to control sample (unprocessed juice) (7.57 Log CFU/ mL). Consequently, MF can be potential candidate in processing of juices against spoilage.

Effect of high shear homogenization on quality characteristics of bael fruit pulp

Response surface methodology was used to investigate the influence of high shear homogenization speed (A: 3000–12000 rpm) and processing time (B: 30–120 min) on bael fruit pulp quality parameters. The experimental results were best fitted in the suggested quadratic model to delineate and envision the responses in terms of color (L*, a*, and b* value), total soluble solids, ascorbic acid, viscosity, and β-carotene content with the highest coefficients of determination (R 2) ranging from 0.80–0.99. Significant (p<0.05) change in the L* value, total soluble solids, ascorbic acid, and β-carotene content was found with change in homogenization speed. The interaction effect of homogenization showed a significant difference in a* value and total soluble solid content of the pulp. The best homogenization conditions were determined via multiple response optimization as 10,682 rpm speed and 43.18 min process time. The quality parameters of the pulp at optimized conditions were observed as L* 15.35, a* 4.51, b* 10.25, ascorbic acid 18.64 mg/100g, viscosity 5349 cP, and β-carotene 4.14 μg/100g. In addition, total phenolic content, flavonoid content, and antioxidant content of homogenized bael fruit pulp was found to significantly (p<0.05) increase from 83.76±1.24 to 119.21±1.35 mg GAE/100 mL, 147.39±0.69 to 156.10±1.11 mg Quercetin equivalent/100 mL and 41.77±0.60 to 66.53±0.41%, respectively. Consequently, this strategy could be used in fruit processing industries to process highly fibrous fruits and non-uniform textured fruit pulp to avoid sedimentation while retaining functionality.

Advances in bioconversion of spent tea leaves to value-added products

Spent tea leaves (STL) are generated after the extraction of liquor from processed tea leaves and are regarded as an underutilized waste. STL are rich in essential amino acids, ω-6 and ω-3 fatty acids, alkaloids (theobromine and caffeine), polyphenols (catechin, theaflavins and rutin) and minerals (Ca, P, K, Mg, Mn) that could be utilized for the production of industrially important products. Vermicomposting, anaerobic digestion, silage preparation and fermentation are currently used as low cost methods for the bioconversion of STL to a usable form. Structural, morphological and chemical modification of STL after suitable bioconversion enables its application in the development of biopolymers, biofuels, catechin derivatives, biochar, absorbents for dye, and for removal of Cd, Hg, Cr(IV), As(V) and aspirin. This review discusses the composition, characterization, bioconversion and value added product generation from STL while highlighting prospective applications of STL in developing battery electrodes, nanocatalysts, insulation materials and edible bioactive peptides.

Microfluidization-Driven Changes in Some Physicochemical Characteristics, Metal/Mineral Composition, and Sensory Attributes of Sugarcane Juice

This work evaluated the effect of microfluidization at different pressure (50, 100, 150, and 200 MPa)-cycle (1, 3, 5, 7) combinations on the physicochemical (total soluble solids, titratable acidity, pH, and electrical conductivity), sensory, and metal/mineral composition of sugarcane juice which was previously unexplored. Juice extracted from blanched sugarcane stems (var Co 0238) was microfluidized, and the analysis for different parameters was conducted using standard protocols. The mineral/metal composition was determined using ICP-OES following a wet digestion method. Results showed that TSS decreased from 18.88 °Brix to a range of 10.15–15.7 °Brix with the former (lower value) being due to the release of insoluble matter after microfluidization which was further solubilised at higher processing cycles (as in the latter). The pH did not vary significantly as compared to control and was in the range of 5.2–5.7. However, a decrease in titratable acidity (0.1–0.26%) was found as compared to control (0.26%). The electrical conductivity of microfluidized sugarcane juice varied from 4.45 to 5.12 mS as compared to 4.95 mS for control. Metal/mineral analysis showed rich reserves of magnesium, phosphorus, potassium, and calcium in sugarcane juice which degraded after microfluidization perhaps due to filtration effect caused by the micropore in the interaction chamber of the microfluidizer. The sensory score showed acceptability of the juice after microfluidization (overall acceptability ∼7).

Nanoencapsulated curcumin emulsion utilizing milk cream as a potential vehicle by microfluidization: Bioaccessibility, cytotoxicity and physico-functional properties

Curcumin loaded milk cream emulsion was microfluidized at different pressures (50-200 MPa) and passes (1-4) using a full-factorial experimental design. Ultrasonicated and microfluidized emulsion was evaluated for particle size, morphological characteristics, antioxidant activity, rheological properties, bioaccessibility and cytotoxicity. Significant reduction was observed in the average particle size (358.2 nm) after microfluidization at 100 MPa/2nd pass. Transmission electron micrographs of the control (homogenized) and microfluidized (100 MPa/2nd pass) samples showed uniform distribution of fat globules in the microfluidized sample with partially dissolved curcumin particles (50-150 nm). Encapsulation efficiency of microfluidized emulsion was found to be significantly higher (97.88%) after processing as compared to control (91.21%). Two-fold (100%) increase in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and 25% increase in ferric-reducing antioxidant power (FRAP) was observed for microfluidized emulsions over control. Infrared spectrums of the emulsion exhibited shift in high intensity peaks indicating bond cleavage after microfluidization. After characterization, emulsions were subjected to in vitro digestion (oral, gastric and intestinal phase) to evaluate its bioaccessibility which was found to be remarkably increased by 30% after microfluidization. For assessing processing induced safety of the formulation, in vitro cytotoxicity of the microfluidized nanocurcumin emulsion was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on HepG2 cells, wherein high % of cell viability (>93%) was seen even at a dose as high as 900 µg/mL revealing no toxic effect of the processing technique (microfluidization). This study highlights the efficacy of microfluidization as a technique and that of milk cream as an inexpensive, yet potential vehicle for generating stable and bio-accessible nano-curcumin emulsion.

Optimization of process parameters for improved chitinase activity from Thermomyces sp. by using artificial neural network and genetic algorithm

Chitinase is responsible for the breaking down of chitin to N-acetyl-glucosamine units linked through (1-4)-glycosidic bond. The chitinases find several applications in waste management and pest control. The high yield with characteristics thermal stability of chitinase is the key to their industrial application. Therefore, the present work focuses on parameter optimization for chitinase production using fungus Thermomyces lanuginosus MTCC 9331. Three different optimization approaches, namely, response surface methodology (RSM), artificial neural network (ANN) and genetic algorithm (GA) were used. The parameters under study were incubation time, pH and inoculum size. The central composite design with RSM was used for the optimization of the process parameters. Further, results were validated with GA and ANN. A multilayer feed-forward algorithm was performed for ANN, i.e., Levenberg-Marquardt, Bayesian Regularization, and Scaled Conjugate Gradient. The ANN predicted values gave higher chitinase activity, i.e., 102.24 U/L as compared to RSM-predicted values, i.e., 88.38 U/L. The predicted chitinase activity was also closer to the observed data at these levels. The validation study suggested that the highest activity of chitinase as predicted by ANN is in line with experimental analysis. The comparison of three different statistical approaches suggested that ANN gives better optimization results compared to the GA and RSM study.