In silico guided pre-treatment of sugarcane juice with natural inhibitors of polyphenol oxidase (PPO) is a new and effective strategy for development of spray-dried formulation

Sugarcane juice is a popular beverage and is also processed to produce sugar. The polyphenol oxidase (PPO) in sugarcane juice causes enzymatic browning and makes the process of sugar production complex and cumbersome. Storage of sugarcane juice is also hampered by the high sugar content and rapid microbial fermentation. The present research assessed the potential of lemon juice (LJ) and ginger extract (GE) as natural inhibitors of PPO. Enzyme kinetics and the mechanism of inhibition of LJ and GE were studied. Primary investigation was carried out using molecular docking approach to assess the inhibitory potential of LJ and GE and to determine the nature of interaction between the enzyme and inhibitors. Extracts were used as inhibitors and studies revealed that both reduced the PPO activity. Subsequently, pure bioactive inhibitors such as ascorbic acid, citric acid, and 6-shogaol present in these natural extracts were used to study the mode of inhibition of PPO. Citric acid decreased PPO activity by lowering pH, while ascorbic acid was found to be a competitive inhibitor of PPO with a K_i of 75.69 µM. The proportion of LJ and GE required in sugarcane juice was optimized on the basis of browning index and sensory acceptance. Further, the sugarcane cane juice after inhibition of PPO under optimized conditions was spray dried and evaluated for reconstitution properties. The product formulated in the present study is a new and effective approach to address quality-compromising issues associated with long-term storage of cane juice.     

The chemistry and medicinal uses of the underutilized Indian fruit tree Garcinia indica Choisy (kokum): A review

Garcinia indica Choisy Syn Brindonia indica, commonly known as kokum and belonging to Guttiferae family, is a plant native to certain regions of India. The trees yield fruits annually in the summer season during the months of March to May. The fruits are green when raw and red to dark purple when fully ripe. They are used to prepare juice, pickles and as acidulant in curries. In the traditional Indian system of medicine the Ayurveda and in various folk systems of medicine, the fruit rinds and leaves are used to treat various inflammatory ailments, rheumatic pain and bowel complaints. The kokum butter prepared from the seed is of both commercial and medicinal use. Chemical studies have shown that the rind contains protein, tannin, pectin, sugars, fat, organic acids like (−)-hydroxycitric acid, hydroxycitric acid lactone and citric acid; the anthocyanins, cyanidin-3-glucoside and cyanidin-3-sambubioside; and the polyisoprenylated phenolics garcinol and isogarcinol. Preclinical studies have shown that kokum or and some of its phytochemicals possess antibacterial, antifungal, anti-ulcerogenic, cardioprotective, anticancer, chemopreventive, free radical scavenging, antioxidant and anti-obesity effects. The present paper reviews the nutritional value, the phytochemical compounds, traditional uses and validated pharmacological properties of kokum.     

Comparative aroma profiles using supercritical carbon dioxide and Likens–Nickerson extraction from a commercial brand of Basmati rice

A comparative evaluation of the extraction of the aroma constituents of a popular commercial brand of Basmati rice using Likens–Nickerson extraction and supercritical fluid extraction (SFE) with carbon dioxide was carried out. SFE at 50 °C and 120 bar for 2 h provided appreciable extraction of the volatile constituents of the rice as compared with Likens–Nickerson extraction. The advantages of smaller sample size, shorter time of extraction and negligible possibility of artefacts with the SFE technique merit its use for recovery of aroma volatiles from Basmati rice. Copyright © 2003 Society of Chemical Industry     

An evolutionary algorithm for broadcast scheduling in wireless multihop networks

A technical challenge in successful deployment and utilization of wireless multihop networks (WMN) are to make effective use of the limited channel bandwidth. One method to solve this challenge is broadcast scheduling of channel usage by the way of time division multiple access (TDMA). Three evolutionary algorithms, namely genetic algorithm (GA), immune genetic algorithm (IGA) and memetic algorithm (MA) are used in this study to solve broadcast scheduling for TDMA in WMN. The aim is to minimize the TDMA cycle length and maximize the node transmissions with reduced computation time. In comparison to GA and IGA, MA actively aim on improving the solutions and is explicitly concerned in exploiting all available knowledge about the problem. The simulation results on numerous problem instances confirm that MA significantly outperforms several heuristic and evolutionary algorithms by solving well-known benchmark problem in terms of solution quality, which also demonstrates the effectiveness of MA in efficient use of channel bandwidth.     

Supercritical Carbon Dioxide Extraction of Squalene from <Emphasis Type="Italic">Amaranthus paniculatus</Emphasis>: Experiments and Process Characterization

Separation of squalene from Amaranthus paniculatus using supercritical carbon dioxide extraction (SC-CO₂) technology and optimization of its process parameters such as temperature, pressure, time of extraction, flow rate of carbon dioxide, and batch size have been conducted. The optimized conditions that provided the best yield of squalene were a sample size of 40 g of amaranth grains of particle diameter of 0.75 mm at a temperature of 100°C and pressure of 550 bar for 1.5 h extracting time at a flow rate of 0.2 L min⁻¹ of carbon dioxide. Solubility of squalene in SC-CO₂ under different operating conditions has also been evaluated using Chrastil equation which showed good agreement with the experimentally obtained yields. Various statistical analyses (regression equations, t test, and analysis of variance) conducted on the extraction parameters concluded that extraction pressure, time and sample batch size have significant effect on the yield of the squalene whereas extraction temperature and particle diameter do not. The results obtained are in accordance to the basic principle of supercritical fluid-phase equilibrium behavior and the solubility isobar and isotherm obtained showed similar trends with those reported for squalene. Using dimensionless numbers, an empirical correlation was also deduced for characterization of the extraction process of squalene in SC-CO₂.     

Studies on Cross-linked A. paniculatas (Rajgeera) Starch

Earlier studies from our laboratories on waxy A. paniculatas starch have shown it to be sensitive to mechanical shear and acidity. Cross-linking of this starch with phosphorus oxychloride at room temperature for ten min using 5 ml POCI₃ per 100 g starch improved the stability under canning conditions, low pH and also mechanical shear. Its paste clarity also improved distinctly. However, it had very poor freeze-thaw stability indicating it to be unsuitable for frozen foods. Evaluation of this starch in canned tomato soup showed it to be a useful thickener for foods processed under retort conditions.     

Utilisation of Amaranthus paniculatas (Rajgeera) Starch in Salad Dressing

Studies on utilisation of Amarantus paniculatas starch in salad dressings showed it to be more stable than corn starch. This is attributed to waxy nature of A. paniculatas starch.     

Supercritical fluid extraction of forskolin from Coleus forskohlii roots

Forskolin (FSK), a labdane diterpene compound having high nutraceutical and therapeutic activity has been extracted from dried Coleus forskohlii roots using supercritical carbon dioxide (SC-CO₂). The solubility parameter of FSK, CO₂, and entrainer solvents was calculated and validated with experimental results. Theoretically, pressure and temperature had significant effect on extraction of FSK. A maximum of 50.32% recovery of FSK was obtained after SC-CO₂ extraction at 40 °C, 250 bar and extraction time of 60 min. Use of methanol as an entrainer at 20% v/w of dried C. forskohlii roots under optimized conditions improved the recovery of FSK to 74.29%. The recovery of FSK further increased marginally to 77.08% when pre-treated with ultrasonication and commercial enzyme preparation of Stargen® 002 and Accellerase® 1500.     

Some Properties of Amaranthus paniculatas (Rajgeera) Starch Pastes

The lysine rich high protein seeds of A. paniculatas (Rajgeera) are reported to contain 50–60% of waxy starch, concentrated in the endosperm. However its food related properties are comparatively unknown. In the present work, paste viscosity, paste clarity, freeze-thaw stability and effect of shear on the viscosity of A. paniculatas starch paste have been studied and compared to corn starch. Also included are the stability of Rajgeera starch paste under pressure cooking (30 min, 15 lb pressure) and acidic conditions (pH 6.98—1.76). Rajgeera starch was found to have a higher paste viscosity, lower paste clarity and high freeze-thaw stability than corn starch. Both Rajgeera and corn starch underwent thinning on being subjected to mechanical shear. Rajgeera starch withstood pressure cooking conditions admirably, but was found to be sensitive to acidic conditions.