Food Engineering Reviews最新文献

Air source heat pump drying systems in the agricultural production sector were reviewed in this study in terms of optimal designs, leading to the optimization of the heat pump drying process. Several intricate designs have been used to optimize the heat pump drying process. Multiple evaporators with multiple condensers, multiple drying chambers, cascade heat pump drying systems, hybrid heat pump drying systems, different configurations of the heat pump components, and refrigerants with lower environmental impacts have been used to accomplish optimal heat pump dryer designs and thereby optimum drying conditions for agricultural products.

The global meat substitute industry is estimated to be worth $8.1 billion by 2026. Prevailing health consciousness among consumers and their concern for the future environment has lifted the concept of meat alternatives from niche to the mainstream. Numerous research findings have emphasized the importance of meat alternatives or substitutes formulated from plant protein, animal cells, and insect-based sources, which emulate the nutritional composition and sensorial properties of animal meat. The current review discusses the necessity of meat substitutes, and their evolution, and bestows an outline of the ongoing research in this field. Novel protein sources such as vegetal proteins (cereal, pulses, oil seeds) and non-vegetal proteins (fungal, air protein, insect, myofibril) are reported to offer a viable alternative to animal meat. However, the functionalities of these proteins and the structuring technique influence the textural properties of the end products. Thus, the selection of a suitable technique is an important aspect in the formulation of the meat alternative. A thorough discussion of various structuring techniques for synthesizing matrixes and fibers with similar textural attributes to that of animal meat has been presented. Furthermore, limitations that confine consumers’ acceptance, the feasibility of scale-up, and the prerequisite for the regulatory framework for meat alternatives have also been pointed out. Overall, the ingredients and techniques of formulation of meat alternatives discussed in detail in this review can provide insight to the researchers and industries in formulating novel meat alternatives.

Tea (Camellia sinensis) is the most widely consumed beverage in the world, with an excellent source of bioactive compounds such as catechins, caffeine, and epigallocatechin. There is an increasing trend to extract these bioactive compounds to deliver them as value-added products. Generally, the extraction of polyphenols and other functional compounds from different parts of tea is carried out using different solvents (e.g., water, water–ethanol, ethanol, methanol, acetone, ethyl acetate, and acetonitrile). The extraction efficiency of functional compounds from tea depends on the type and polarity of the solvent as well as the applied process. Several conventional techniques, such as boiling, heating, Soxhlet, and cold extraction, are used to extract bioactive ingredients. However, these procedures are unsuitable for achieving high yields and biological activities due to the long extraction times of cold brewing and the high temperatures in other heating methods. Many efforts have been carried out in food and pharmaceutical industries to replace conventional extraction techniques with innovative technologies (e.g., microwave (MAE), ultrasonic (UAE), pressurized liquid (PLE), pulsed electric field (PEF), and supercritical fluid (SFE)), which are fast, safe, energy-saving, and can present eco-friendly characteristics. These innovative extraction techniques have proven to improve the recovery rate of phenolic-based antioxidant compounds from tea and increase their extraction efficiency. In this review, the application of novel processing technologies for the extraction of value-added compounds from tea leaves is reviewed. The advantages and drawbacks of using these technologies are also highlighted.

Annually, one-third of the food produced globally is lost or wasted. A considerable portion of global food waste comprises dry foods that are rejected due to their unattractive appearance. One effective technique to solve this problem is by developing dryers that consistently produce dry foods that are visually appealing and have a long shelf life. The beating heart of such dryers is a computer vision (CV) system that monitors the visual attributes of the food, in real time, during the drying process. Unfortunately, there are currently no real-time CV systems for monitoring the visual attributes of food during fluidized bed drying. This setback is linked to figure-ground separation challenges encountered while segmenting real-time images of the food. Sadly, when current CV systems are used to monitor visual attributes of food during fluidized bed drying, these CV systems fail miserably because they are not designed to account for three major dryer-dependent determinants—the layout, the state and pattern of motion, and the behavior of food materials within the image captured during fluidized bed drying. To solve this lingering problem, this paper reviewed various computer vision systems based on the three determinants. This study revealed that input images for the different CV systems can be categorized as being either static-type images or chaotic-type images. The CV systems were grouped into “Static-input offline CV systems,” “Static-input online CV systems,” and “Chaotic-input online CV systems.” Building on the insight gained while reviewing the three classes of CV systems, two novel AI-driven solutions for monitoring visual attributes of food, in real time, during fluidized bed drying were proposed. The first solution was a “two-pass” deep learning system that predicts visual attributes from segmented results. While the second solution was a “single-pass” deep learning system that by-passes the segmentation step, thus saving computational cost. When such AI-driven solutions are merged with a control system and then integrated with fluidized bed dryers, this union could open the gateway to intelligent drying, where dryers consistently produce high-quality dry foods. By extension, consistency in product quality could reduce global food losses and waste significantly.

Abstract

Separation of two fluids or particles from an emulsion is a fundamental process in many applications such as creaming of milk in dairy sector and extraction of various oils (avocado oil, palm oil, etc.) among many others. The aim of this paper is to elaborate on the development of various methods and technologies employed for the separation process including gravity, chemical, and centrifugation as well as the newer acoustic separation technology. Influential parameters affecting the performance, advantages, and disadvantages for each method will be discussed and compared. Various transducer configurations and corresponding experimental set-ups and operating parameters are also examined for acoustic separation. Accordingly, the future trend is proposed for introducing new transducer configurations to diminish or preferably eliminate the current disadvantages and barriers and to improve the separation process performance.

Grain drying is a vital operation in preparing finished grain products such as flour, drinks, confectioneries and infant food. The grain drying kinetics is governed by the heat and mass transfer process between the grain and the environment. Incomplete, improper and over-drying are crucial to the grain quality and negatively influence the acceptance of the grain by the consumers. Dried grain moisture content is a critical factor for developing grain drying systems and selecting optimal performance by researchers and the grain processing industry. Many grain drying technologies such as fluidised bed dryers, fixed bed dryers, infrared dryers, microwave dryers, vacuum dryers and freeze dryers have been used in recent years. To improve the drying process of grain, researchers have combined some drying technologies such as microwave + hot air, infrared + hot air and microwave + a fluidised bed dryer. Also, they introduce some treatments such as ultrasound dielectric and dehumidification. These methods enhance the dryer performance, such as higher moisture removal, reduced processing time, higher energy efficiency and nutrient retention. Therefore, this review focused on the drying conditions, time, energy consumption, nutrient retention and cost associated with the reduction of moisture content in grain to a suitable safe level for further processing and storage.

Currently, statistical experimental design is employed as a quality control method to produce excellent products at the lowest possible cost in food processing, speeding up the process of developing new foods, cutting down costs associated with research, easing the process of moving food products from the research and development stage to the manufacturing stage, and troubleshooting manufacturing issues. In the extraction of bioactive compounds from food, the optimization procedure becomes more straightforward as the optimum conditions of the numerous evaluated responses converge to a similar section. However, the problem becomes more complicated when the optimum values for each response go further apart, making it harder to discover settings that satisfy all of them simultaneously. Using a mathematical function, multiple responses can be integrated into a single one in another manner. The generated response surface enables the calculation of optimum values for extraction parameter, which fulfills all responses whenever possible. Hence, this article reviewed multiple responses, desirability function, and graphical optimization solutions employed to extract food bioactive compounds in the last decade. These techniques’ benefits, drawbacks, potentials, and applications were discussed, including some of their uses in the extraction of bioactive compounds. This will help to address the actual mathematical and statistical issues that arise during the multiple response extraction of food bioactive compounds.

Graphical Abstract

Solar dryers have always been criticized for their lower performances. There are numerous ways to define the performance of a solar drying system such as thermal performance, drying kinetics, environmental aspects, economic evaluations, and quality of the dried product. Different modeling techniques have also been developed to design and analyze solar dryers and drying processes. This article presents a systematic, comprehensive, and state-of-the-art overview of various performance indicators and modeling techniques used for the evaluation and analysis of solar dryers, especially domestic and low cost solar dryers. Environmental analysis has severe global implications, and product quality is one of the biggest concerns of consumers. But the environmental impact and product quality assessments for domestic solar dryers are observed to be rarely reported in the literature. The use of modeling techniques in solar drying has changed the way of analyzing any thermal system. Here, an attempt is made to establish an overall assessment criterion for domestic solar dryers and to give a one-stop solution for researchers and users around the world.

Abstract

Dairy products, such as liquid, powdered, and fermented milk, provide an excellent source of nutrition and constitute part of a well-balanced diet. However, measures to prevent the deterioration of the quality of dairy products during thermal treatment and storage are lacking at present. Deterioration of milk quality is primarily related to reactions of oxidation, hydrolysis, and Maillard reaction. While multiple studies have focused on the factors influencing the deterioration of dairy products during processing and storage, systematic analysis of the underlying mechanisms is essential to improve our overall understanding of the process. This report presents a structured overview of the mechanisms and markers associated with deterioration reactions in marketed dairy products. The overall impacts of deterioration reactions on the quality and flavor of dairy products are additionally reviewed. Furthermore, potential markers of deterioration reactions and future development directions of the dairy industry are discussed, with a view to providing a reference for the quality and safety guarantee of dairy products.

Graphical Abstract