Ozone: An Advanced Oxidation Technology for Starch Modification

ABSTRACT

Ozone processing is one of the encouraging non-thermal and bio-friendly techniques in the food processing sector. The applicability of ozone technology in food industry is increasing due to its antimicrobial action and modification of functional properties of the foods. The structural modifications of starches have major applications in the food and bakery industry for producing products with increased shelf life, improved texture, and retention of moisture content. The positive response of ozonation in carboxyl and carbonyl group alters the viscosity of starch molecules. Rheological characteristics like low viscosity even at an increased concentration, desirable binding properties, and film-forming ability have increased its use in the food processing industry. The influence of ozonation in the physicochemical properties is mainly retrogradation and cross-linking of amylose and amylopectin molecules and enzymatic modifications. Ozonation cause change in crystallinity, viscosity, expansion ratio, and gelatinization temperatures. Finally, ozonation induces many possible changes in native starches for the effective utilization in the processing sectors. In this review, starch modifications utilizing ozone and various research achievements and scientific reports focusing on the effect of ozonation in terms of physical, chemical, and thermal properties of native starches and on the possible modifications have been summarized and discussed. In conclusion, ozone is a green technology that can be effectively used as an alternative oxidation technique for starch modification.     

Numerical Simulation and Validation of Ozone Concentration Profile in Green Gram (Vigna radiate) Bulks

The new fumigant ozone offers an alternative to contact insecticides such as phosphine and methyl bromide as a grain fumigant. This study was carried out to test the flow characteristics of ozone from points of release to the available concentration of ozone to kill pests at other areas along the storage bin. A mass transfer model which predicts ozone concentration as a function of time was applied along with continuity equation to simulate the ozone transfer in a storage bin. Ozone exchange rate based on grain bed thickness was taken into account and evaluated using the correlation developed during the experiment. The relative error between the experimental and predicted ozone concentration values for the entire bin geometry was less than 25.7%. Overall, the general trends of measured ozone concentration were compatible with the simulated ones.     

Ozone based food preservation: a promising green technology for enhanced food safety

Extending shelf life of food products is a major concern of the producers, and the food industry requires ‘greener’ alternatives to the current technologies. Ozone-based food preservation may suit this niche. Ozone is an attractive alternative preservative that food industry needs due to its properties such as quick decomposition and little residual effect during food preservation. Ozone is the strongest molecule available for the disinfection of water and is second only to elemental fluorine in oxidizing power. Ozone is being used in the food industry in various applications such as decontamination of water and equipment surfaces. Several researchers have focused on the application of ozone to inactivate microorganisms on fresh produce, like fruits, vegetables, meat, poultry, fish, and eggs, and dry produce, such as cereals, pulses, and spices. This review comprehensively analyses appropriate ozone concentrations and exposure times and discusses various factors that affect the quality and safety of food products during ozonation.     

Caspase-3-generated fragment of gelsolin: effector of morphological change in apoptosis

The caspase-3 (CPP32, apopain, YAMA) family of cysteinyl proteases has been implicated as key mediators of apoptosis in mammalian cells. Gelsolin was identified as a substrate for caspase-3 by screening the translation products of small complementary DNA pools for sensitivity to cleavage by caspase-3. Gelsolin was cleaved in vivo in a caspase-dependent manner in cells stimulated by Fas. Caspase-cleaved gelsolin severed actin filaments in vitro in a Ca2+-independent manner. Expression of the gelsolin cleavage product in multiple cell types caused the cells to round up, detach from the plate, and undergo nuclear fragmentation. Neutrophils isolated from mice lacking gelsolin had delayed onset of both blebbing and DNA fragmentation, following apoptosis induction, compared with wild-type neutrophils. Thus, cleaved gelsolin may be one physiological effector of morphologic change during apoptosis.     

Aqueous ozone: Chemistry,physiochemical properties,microbial inactivation,factors influencing antimicrobial effectiveness,and application in food

The need for sustainable food production and the demand for fresh and minimally processed foods have prompted remarkable research in novel food processing technologies that ensure safe and shelf-stable food for a large population. Long-established techniques such as heating, drying, and freezing have been associated with nutrient loss and high energy consumption. This trend has drawn attention to the practice of employing ozone in several food applications owing to its significant disinfectant and antimicrobial efficiency. The aqueous form of ozone has been found to show greater efficacy than its gaseous form, with faster decomposition rates leaving no harmful residues. The current study presents an overview of the latest scientific literature on the properties, chemistry, and generation of aqueous ozone, emphasizing the factors affecting process efficiency. The review scrupulously focuses on food decontamination, starch modification, pesticide degradation, and seed germination effects of aqueous ozone, highlighting the optimum processing parameters and salient findings of some major studies. A brief insight into the limitations and future trends has also been presented. Aqueous ozone has been acclaimed to have the potential to cause significant changes in the food matrix that could result in constructive modifications with outcomes entirely dependent on the processing conditions. Indirect and direct reactions involving hydroxyl radical and molecular oxygen atoms, respectively, form the basis of the ozone reaction in aqueous media, providing a distinctive kind of advanced oxidation process that offers certain crucial benefits. With a shorter half-life in water as compared to air, the rapid decomposition of aqueous ozone to oxygen, leaving no harmful residues, adds to its advantages.     

Impact of Ozone Treatment on Seed Germination – A Systematic Review

ABSTRACT

Rising world population necessarily increases the food requirement. At the same time, agricultural land has been reduced drastically due to the rapid urbanization and industrialization which severely affects the land availability for the growers. However, the enhancement of seed germination has the potential to secure the food safety of masses by improving crop production. The traditionally followed chemical methods to improve seed germination have major limitations including being environmentally unhealthy, time-consuming, and are labor-intensive. Of late the application of ozone on plant growth and seed germination has attained greater significance. This promising technique and its various potential applications in the food industry have started emerging. Ozone is a strong antimicrobial agent as well as a germination enhancer. Ozone, in limited quantity, enhances seed germination rate; on the other hand, excess ozone can also cause some negative effects. Generally, ozone is applied either in gaseous or aqueous phases; however, the method and treatment conditions of ozone vary with the subject samples. This review mainly discusses the impact of ozone treatment on seed germination, the quality changes that accompany the treatment as well as the factors affecting the efficiency of ozone.     

Engineering properties of five varieties of coconuts (Cocos nucifera L.) for efficient husk separation

ABSTRACT

Coconut husk is used as a natural fiber, and it is constantly gaining economic importance including in organic farming. Yet, there are major knowledge gaps regarding the engineering properties of coconut to design efficient coconut dehusking and coir manufacturing process. A sample of 40 coconuts of each variety, namely Malayan Yellow Dwarf, Malayan Orange Dwarf, Kera Shankara, Chowghat Orange Dwarf, and Chowghat Green Dwarf, were divided into two groups (20 dry and 20 green coconuts), and different engineering properties were measured. It was observed that coconuts show an extensive diversity in size, density, husk thickness, husk weight, shell thickness, shell weight, and kernel thickness, depending on variety and maturity. The present investigation provides necessary information and the need for classifying the coconut fruits based on size/variety rather than weight to design superior coconut dehusking machine.     

Numerical Simulation and Validation of Mass Transfer Process of Ozone Gas in Rice Grain Bulks

Ozone is a potential alternative to commercial fumigants. The development of ozone fumigation technology for insects control requires a precise prediction of the distribution of introduced ozone gas in grain bulks. Hence, this study was conducted to investigate the mass transfer process of ozone gas in rice grain bulks. Experiments were conducted in a 0.6-m diameter flat-bottom bin filled with rice grains and ozonated using 5 g h^?1 capacity ozone generator. Simulation of transfer process of ozone through the rice grain bulks was conducted using the principle of the law of conservation employing the continuity equation. The experimental data for ozone transfer through connected the column of rice was used to validate the model. The relative error between the actual and predicted ozone concentration for the entire bin geometry was less than 33%. The predictions from the projected model were in accordance with the ozone concentrations obtained from the experimental results.     

Application and Kinetics of Ozone in Food Preservation

Ozone is activated oxygen and it is referred to as a triatomic form of oxygen. It is a natural agent and has a broad antimicrobial property, which together with an oxidation potential, make it an attractive option for the food industry. This article focuses on the use of ozone for preservation of vegetables, fruits and fruit juices, and highlights the inactivation mechanism of microorganisms. The application of ozone in grain storage and the quality of ozone treated grains is discussed, along with the reaction kinetics of ozone in grains.