Influence of Novel Infrared Freeze Drying of Rose Flavored Yogurt Melts on Their Physicochemical Properties, Bioactive Compounds and Energy Consumption

Effects of infrared heating as an emerging thermal technology on physicochemical properties of foods

Infrared (IR) radiation is part of an electromagnetic spectrum between the ultraviolet and microwave regions. IR radiation impacts the surface of the food, generating heat that can be used as an efficient drying technique. Apart from drying, IR heating is an emerging food processing technology with applications in baking, roasting, microbial inactivation, insect control, extraction for antioxidant recovery, peeling, and blanching. Physicochemical properties such as texture, color, hardness, total phenols, and antioxidants capability of foods are essential quality attributes that affect the food quality. In this regard, the main objective of this review study was to highlight and discuss the effects of IR heating on food quality to expand its food applications and commercial adoption. The fundamental mechanisms, type of emitters, and IR processing parameters are discussed in this review to explore their impacts on food quality. Infrared heating has been shown that the appropriate operating conditions (distance, exposure time, IR power, and temperature) with high heat transfer, thus leading to a shorter drying time. Besides, IR heating used in food processing to improve food-surface color and flavor, it also enhances hardness, firmness, shrinkage, crispiness, and viscosity. Meanwhile, antioxidant activity is enhanced, and some nutrients are retained.

Instant quinoa prepared by different cooking methods and infrared-assisted freeze drying: Effects of variables on the physicochemical properties

The effects of cooking methods (pressure cooking, microwave cooking, and atmospheric pressure cooking) and infrared-assisted freeze drying (IRFD) on drying characteristic, crystalline structure, pasting property, rehydration behavior, microstructure, texture, and flavor of instant quinoa samples were investigated. Results showed that IRFD significantly reduced the drying time needed for freeze drying (FD). The crystalline structure of starch in raw quinoa was destroyed in cooking process, IRFD process well maintained the gelatinized state of quinoa samples. The pressure cooked samples owned the highest porosity and best rehydration ability. Pressure cooking and microwave cooking caused the softer and thicker texture of rehydrated instant quinoa samples. As for the flavor of quinoa sample, IRFD possessed the stronger retention ability compared with FD. In summary, pressure cooking and IRFD could be the applicable processing methods for the production of instant quinoa product or other dehydrated instant product with high quality.

Improving drying kinetics, physicochemical properties and bioactive compounds of red dragon fruit (Hylocereus species) by novel infrared drying

Effects of tray rotation speeds (TRS: 0, 20, 40 rpm), temperatures (50, 60, 70 °C) and wavelength spectra (mid and near-infrared) were comparatively evaluated on improving drying kinetics, physicochemical properties and bioactive content of red dragon fruits. Results indicated that successive increases in TRS and temperature led to significant reductions in drying time and increases in drying rates and moisture diffusivity. High TRS (40 rpm) and lower temperatures (50, 60 °C) also improved colour, total soluble solids, rehydration ratio, total phenolics and flavonoid contents, betalain content and antioxidant activity. Meanwhile, NIR drying presented a more energy-efficient approach, but with substantial reductions in quality properties compared with MIR drying. Overall, the results suggested the importance of wavelength absorption properties of plant tissues and potential avoidance of localized overheating for enhanced efficiency during infrared drying and prompted the development of suitable approaches and optimization studies for improving efficiency.

The Compositional Aspects of Edible Flowers as an Emerging Horticultural Product

Edible flowers are becoming very popular, as consumers are seeking healthier and more attractive food products that can improve their diet aesthetics and diversify their dietary sources of micronutrients. The great variety of flowers that can be eaten is also associated with high variability in chemical composition, especially in bioactive compounds content that may significantly contribute to human health. The advanced analytical techniques allowed us to reveal the chemical composition of edible flowers and identify new compounds and effects that were not known until recently. Considering the numerous species of edible flowers, the present review aims to categorize the various species depending on their chemical composition and also to present the main groups of compounds that are usually present in the species that are most commonly used for culinary purposes. Moreover, special attention is given to those species that contain potentially toxic or poisonous compounds as their integration in human diets should be carefully considered. In conclusion, the present review provides useful information regarding the chemical composition and the main groups of chemical compounds that are present in the flowers of the most common species.

Infrared Drying Trends Applied to Fruit

Aims: This article seeks to identify the main products to which drying is applied, mainly by infrared, as well as the mathematical models used to evaluate a product.

Background: The drying of agro-industrial products is a very important unitary operation to avoid post-harvest losses.

Objective: This article looks to respond to the following questions: Which raw materials are subjected to far-infrared drying? What are the mathematical models used in the application of far-infrared?

Method: To identify the most focused articles on the topic, we worked with the search equation “TITLE-ABS-KEY (‘infrared drying’) AND fruits AND [LIMIT-TO (SUBJAREA, ‘AGRI’) OR LIMIT-TO (SUBJAREA, ‘ENGI’)],” which was run in the Scopus database for scientific articles.

Result: After knowing the different technologies, more than 23 applications in agro-industrial products were identified. In these applications, it is observed how quality is one of the most important factors in the preservation of dehydrated products; far-infrared drying helps retain sensory quality in products such as sweet potatoes, grapes, Cordyceps militaris, and mangoes.

Conclusion: A common factor that could be found from the articles and patents was the application of this infrared drying technique in fruits and vegetables with high water content, such as kiwi, chives, and mushroom varieties. These articles and patents based their studies on optimizing the technique by varying drying times, temperatures, and pressures, even sometimes combining different drying techniques—all to preserve the organoleptic characteristics of the product, avoiding damage to thermolabile compounds and obtaining a dry food of very good quality, performance, and characteristics.

Investigation on spontaneous 4D changes in color and flavor of healthy 3D printed food materials over time in response to external or internal pH stimulus

This study aimed to investigate 4D changes in colors and flavors of 3D-printed healthy food products in response to an external or internal pH stimulus. The formulations obtained by 3D printing of multi-smart materials, comprised of the combination of red cabbage juice, vanillin powder, potato starch and different fruit juices were used. 3D printing ability of red cabbage juice and vanillin powder affected by different potato starch concentrations was first studied. Then, changes in color, texture, flavor (by E-nose) and taste (by E-tongue) induced by the stimulus were determined. Results revealed that the color of the 3D-printed product changed from blue (control sample) to red, purple, violet, blue, blue-green, and green-yellow colors when sprayed with pH solutions of 2, 3-4, 5-6, 7, 8-9, and 10, respectively. In addition, clear differences in aroma and taste profiles among pH samples were detected. Moreover, dried 4D product samples exhibited color and anthocyanins stability when stored in ambient temperature for three weeks. This study is important for manufacturing new healthy 3D-printed food products with desired and attractive sensory characteristics, which can be particularly significant to people with poor appetite.