Recent advances in optical fiber high-temperature sensors and encapsulation technique[Invited]

In the aerospace field,for aerospace engines and other high-end manufacturing equipment working in extreme environments,like ultrahigh temperatures,high pressure,and high-speed airflow,in situ temperature measurement is of great importance for improving the structure design and achieving the health monitoring and the fault diagnosis of critical parts.Optical fiber sensors have the advantages of small size,easy design,corrosion resistance,anti-electromagnetic interference,and the ability to achieve distributed or quasi-distributed sensing and have broad application prospects for temperature sensing in extreme environments.In this review,first,we introduce the current research status of fiber Bragg grating-type and Fabry–Perot interferometer-type high-temperature sensors.Then we review the optical fiber hightemperature sensor encapsulation techniques,including tubular encapsulation,substrate encapsulation,and metalembedded encapsulation,and discuss the extreme environmental adaptability of different encapsulation structures.Finally,the critical technological issues that need to be solved for the application of optical fiber sensors in extreme environments are discussed.

Encapsulation in the Food Industry: A Brief Historical Overview to Recent Developments

Encapsulation in food industry serves several functions including masking of undesirable color/flavor/taste, preservation of unstable constituents, incorporation of additional functional and nutritional components and site-specific release of encapsulated ingredients at a controlled time and rate. The knowledge of microencapsulation in other sectors like pharmaceutical industry is well advanced;however, more understanding is required to harvest the maximum benefits from food industry. This paper started with highlighting the gradual progress of microencapsulation process in food industry and ended up with some invaluable suggestions for future works. In the body, the paper reviews the major techniques of food encapsulation, choices of coating materials and the performance measurement methods of food encapsulation. Future trends, scopes and aspects of microencapsulation process in food manufacturing sector are also presented as the necessary recommendations for future researches. The article would help the microencapsulated food manufacturers to choose the target oriented encapsulates and suitable encapsulation technique.

Encapsulation-based technologies for bioactive compounds and their application in the food industry:A roadmap for food-derived functional and health-promoting ingredients

Some of the most commonly used agri-food products worldwide are vegetable and fruit-based products that are rich in bioactive compounds such as vitamins,polyphenols,and other antioxidants.However,many of these molecules are sensitive and susceptible to oxidation and degradation during food processing,particularly when exposed to heat.This review examines the effect of encapsulation on bioactive compounds and how encapsulation technologies can be leveraged in the food industry to protect and optimize the functional properties of naturally occurring food bioactives.Encapsulation can also assist with the creation of desirable sensory attributes(e.g.,aroma,texture,color,and taste),thus playing a major role in the design and development of novel foods and beverages.Encapsulation is one of the few technologies experiencing continued growth due to its unique potentialities,high versatility and extensive range of applications.Various types of food grade encapsulating materials,also known as wall,coating,shell or carrier,can be employed,including proteins,polysaccharides(e.g.,gums),other biopolymers,and lipids.Encapsulation owes its success to its proven record as an effective process for preserving the encapsulated bioactives from the surrounding conditions,while assisting with optimized delivery and controlled release of the transported active compounds.Among the multiple variations and applications of encapsulation,micro-and nanoencapsulation of food-derived bioactives are the main focus of this review,which discusses the underlying principles,technological developments,as well as current and foreseeable applications aimed at protecting and enhancing the functionalities of biologically active ingredients in food systems.