Processing and Food Engineering

Microencapsulation is defined as a process in which tiny particles or droplets are surrounded by a coating or embedded in a homogeneous or heterogeneous matrix, to give small capsules with many useful properties. It is a technique by which liquid droplets, solid particles or gas compounds are entrapped into thin films of a food grade microencapsulating agent. Microencapsulation is a smart manner of improving the performance of products. By using this technology, an active of interest can be isolated and kept unmodified for extended periods of time. This technique has been employed in a diverse range of fields from food processing, chemicals and pharmaceuticals to cosmetics and printing. For this reason, widespread interest has developed in microencapsulation technology. There were several methods for undergoing the process of microencapsulation like spray drying, spray cooling, spray chilling, fluidised bed coating, Pan coating etc. All these methods were discussed briefly in this review.

Browntop millet (Urochloa ramose L.) known as 'korale' in Karnataka is an annual warm-season grass often used as a forage crop gaining importance because of its nutritional qualities. Very fewer researches have been done so far on the millet. The research was conducted to determine the physical properties of the browntop millet. The physical properties were determined at moisture content 11.2 ± 0.16 (w.b). The mean values of length, width and thickness of the browntop millet were found to be 3.00 ± 0.21, 1.79 ± 0.10 and 1.15 ± 0.09 mm, respectively. The geometric mean diameter and arithmetic mean diameter were 1.82 ± 0.09 and 1.99 ± 0.1 mm, respectively. The mean weight of 1000 browntop millet seeds was 3.42 ± 0.14 g. The bulk density and true density were 601.17 ± 4.08 and 1305.47±95.5 kg/m 3 , respectively. The mean porosity, aspect ratio and sphericity were found to be 53.74 ± 3.23, 58.58 ± 3.84 and 59.82 ± 2.60%, respectively. The shape of the browntop millet was oval. The angle of repose was 27°47' ± 0.21 and the coefficient of friction for the three surfaces namely, Glass, Aluminum and Wooden Sheets were 0.62 ± 0.0009, 0.59 ± 0.0051 and 0.6 ± 0.0063, respectively. The terminal velocity was 7.2 m/sec. The tristimulous colour values (L*, a* and b*) were found to be 60.45 ± 0.44, 3.78 ± 0.06 and 14.71 ± 0.33, respectively. Hence this study helps agricultural and food engineers, designers, scientists and processors towards design of equipment and efficient process for browntop millet grain processing.

High Pressure Processing (HPP) is an emerging process technique which makes food safer and extends its shelf life. Unlike most conventional heat treatments, it is a non-thermal preservation and pasteurization technique that causes little or no change in the organoleptic and nutritional attributes of the product being processed. High-Pressure Processing (HPP) using 100 MPa to >1,000 MPa for short period and has been shown to enhance safety and extending shelf-life, free from additives with minimal influence on the sensory, physical and nutritional properties of the food and minimizes the microorganisms to the safe level. It meets consumer demand for freshness without the negativity often associated with other methods such as irradiation. This paper reviews the literature on high pressure application in food industry, principles of High-Pressure Processing, types of HPP, advantages and limitations of HPP.

Mulberries are recognized botanically as Morus which is a species of blossoming plants in Moraceae family. The mulberry leaves are used as a functional food, mostly in the form of herbal tea. The drawback in the traditional method of mulberry leaf processing is the loss of antioxidant properties during drying. Hence, this manuscript focuses on different techniques used in the processing of mulberry leaves. Drying is the most important unit operation for the processing of mulberry leaves and antioxidant properties are directly dependent on drying temperature (40-70 ºC). The extraction yield, solvent consumption, extraction time and quality of extracts can be improved by the use of high-pressure, microwave, ultrasound, and supercritical fluids. The encapsulation process provides the stability and improves the shelf-life of bioactive components in mulberry leaves. The leaves extract in different value added form significantly helps to lower blood sugar, inflammation levels, and fighting against heart disease.