Changes in amino acids and bioactive compounds of pigmented rice as affected by far-infrared radiation and hot air drying

Changes in chemical composition, volatile compound, and bioactive compounds retention in shallots (Allium ascalonicum L.) under different drying methods

Shallots (Allium ascalonicum L.) are widely used in culinary and medicinal applications due to their rich bioactive compounds and health benefits. This study examines the effects of freeze drying, sun drying, and hot air drying at 40, 60, and 80 °C on chemical and bioactive compounds in shallots. Hot air drying at 80 °C had the highest total phenolic and flavonoid contents. Freeze drying increased syringic, p-coumaric, protocatechuic, vanillic, and ferulic acids. Quercetin was highest in freeze drying. Apigenin increased in samples that was dried by hot air drying at 80 °C. Proline was the major amino acid; arginine increased by 34 % in sun drying. Fourier Transform Infrared Spectroscopy (FTIR) revealed polysaccharides, lipids-proteins, and amino acids. Eucalyptol was the predominant volatile component in fresh shallot and most preserved by freeze drying. The results underscore the significance of choosing suitable drying methods to preserve shallot bioactive compounds and antioxidant properties.

An integrated and rapid evaluation of Curcumae Radix from different botanical origins based on chemical components, antiplatelet aggregation effect and Fourier transform near-infrared spectroscopy

Curcumae Radix (CR) is a widely used traditional Chinese medicine with significant pharmaceutical importance, including enhancing blood circulation and addressing blood stasis. This study aims to establish an integrated and rapid quality assessment method for CR from various botanical origins, based on chemical components, antiplatelet aggregation effects, and Fourier transform near-infrared (FT-NIR) spectroscopy combined with multivariate algorithms. Firstly, ultra-performance liquid chromatography-photodiode array (UPLC-PDA) combined with chemometric analyses was used to examine variations in the chemical profiles of CR. Secondly, the activation effect on blood circulation of CR was assessed using an in vitro antiplatelet aggregation assay. The studies revealed significant variations in chemical profiles and antiplatelet aggregation effects among CR samples from different botanical origins, with constituents such as germacrone, β-elemene, bisdemethoxycurcumin, demethoxycurcumin, and curcumin showing a positive correlation with antiplatelet aggregation biopotency. Thirdly, FT-NIR spectroscopy was integrated with various machine learning algorithms, including Artificial Neural Network (ANN), K-Nearest Neighbors (KNN), Logistic Regression (LR), Support Vector Machine (SVM), and Subspace K-Nearest Neighbors (Subspace KNN), to classify CR samples from four distinct sources. The result showed that FT-NIR combined with KNN and SVM classification algorithms after SNV and MSC preprocessing successfully distinguished CR samples from four plant sources with an accuracy of 100%. Finally, Quantitative models for active constituents and antiplatelet aggregation bioactivity were developed by optimizing the partial least squares (PLS) model with interval combination optimization (ICO) and competitive adaptive reweighted sampling (CARS) techniques. The CARS-PLS model achieved the best predictive performance across all five components. The coefficient of determination (R2p) and root mean square error (RMSEP) in the independent test sets were 0.9708 and 0.2098, 0.8744 and 0.2065, 0.9511 and 0.0034, 0.9803 and 0.0066, 0.9567 and 0.0172 for germacrone, β-elemene, bisdemethoxycurcumin, demethoxycurcumin and curcumin, respectively. The ICO-PLS model demonstrated superior predictive capabilities for antiplatelet aggregation biotency, achieving an R2p of 0.9010, and an RMSEP of 0.5370. This study provides a valuable reference for the quality evaluation of CR in a more rapid and comprehensive manner.

Advancement and Innovations in Drying of Biopharmaceuticals, Nutraceuticals, and Functional Foods

Drying is a crucial unit operation within the functional foods and biopharmaceutical industries, acting as a fundamental preservation technique and a mechanism to maintain these products' bioactive components and nutritional values. The heat-sensitive bioactive components, which carry critical quality attributes, necessitate a meticulous selection of drying methods and conditions backed by robust research. In this review, we investigate challenges associated with drying these heat-sensitive materials and examine the impact of various drying methods. Our thorough research extensively covers ten notable drying methods: heat pump drying, freeze-drying, spray drying, vacuum drying, fluidized bed drying, superheated steam drying, infrared drying, microwave drying, osmotic drying, vacuum drying, and supercritical fluid drying. Each method is tailored to address the requirements of specific functional foods and biopharmaceuticals and provides a comprehensive account of each technique's inherent advantages and potential limitations. Further, the review ventures into the exploration of combined hybrid drying techniques and smart drying technologies with industry 4.0 tools such as automation, AI, machine learning, IoT, and cyber-physical systems. These innovative methods are designed to enhance product performance and elevate the quality of the final product in the drying of functional foods and biopharmaceuticals. Through a thorough survey of the drying landscape, this review illuminates the intricacies of these operations and underscores their pivotal role in functional foods and biopharmaceutical production.

Comparative elucidation of bioactive and antioxidant properties of red dragon fruit peel as affected by electromagnetic and conventional drying approaches

The effects of near-infrared (NIRD), mid-infrared (MIRD), far-infrared (FIRD), microwave (MWD), and hot air drying (HAD) on drying kinetic, colour, phytochemical composition, and antioxidant activity of red dragon fruit peel (RDFP) was evaluated. Results indicated that drying methods induced varying microstructural and chemical changes on RDFP, significantly influencing moisture removal rates and phytochemical retention. The lowest drying time was observed for MWD, while MIRD presented the highest drying time. FIRD drying was more favourable for retaining TPC, TFC, betacyanin and betaxanthin, while the ascorbic acid content was better retained during MIRD and NIRD. Enhancements in ABTS, CUPRAC and reducing power were associated with FIRD, and NIRD and MIRD enhanced DPPH and HRSA. Overall, chemical modifications induced by drying improved the phytochemical and antioxidant properties but presented adversative effects on ascorbic acid and DPPH. The study presented an essential background for the optimal drying of RDFP.

Increasing the Amounts of Bioactive Components in American Ginseng (Panax quinquefolium L.) Leaves Using Far-Infrared Irradiation

Both the roots and leaves of American ginseng contain ginsenosides and polyphenols. The impact of thermal processing on enhancing the biological activities of the root by altering its component composition has been widely reported. However, the effects of far-infrared irradiation (FIR), an efficient heat treatment method, on the bioactive components of the leaves remain to be elucidated. In the present study, we investigated the effects of FIR heat treatment between 160 and 200 °C on the deglycosylation and dehydration rates of the bioactive components in American ginseng leaves. As the temperature was increased, the amounts of common ginsenosides decreased while those of rare ginsenosides increased. After FIR heat treatment of American ginseng leaves at an optimal 190 °C, the highest total polyphenolic content and kaempferol content were detected, the antioxidant activity was significantly enhanced, and the amounts of the rare ginsenosides F4, Rg6, Rh4, Rk3, Rk1, Rg3, and Rg5 were 41, 5, 37, 64, 222, 17, and 266 times higher than those in untreated leaves, respectively. Moreover, the radical scavenging rates for 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and the reducing power of the treated leaf extracts were 2.17, 1.86, and 1.77 times higher, respectively. Hence, FIR heat treatment at 190 °C is an efficient method for producing beneficial bioactive components from American ginseng leaves.

Spectral selective infrared heating of food components based on optical characteristics and penetration depth: a critical review

Infrared (IR) radiation has been used in food processing applications for its unique high heating efficiency. There is a great need to address the radiation absorption and heating effect during the application of IR in the processing of foods. The radiation wavelength determines the nature of the processing, and it is mainly affected by the type of emitter, operating temperature, and the power supplied. The penetration depth of the IR on food material plays a critical role in the heating level along with the optical characteristics of the IR and food product. The IR radiations cause a significant change in the food components like starch, protein, fats and enzymes. The facility to generate wavelength-specific radiation output can hold the potential of momentously increasing the efficiency of IR heating operations. IR heating is gaining importance in 3D and 4D printing systems, and the application of artificial intelligence in IR processing is being explored. This state-of-art review gives a detailed view of the different emitters of IR and mainly emphasizes the behavior and changes of major food components during IR treatment. The penetration depth of IR, optical characteristics and selective spectral heating based on the target product are discussed.

Effects of Far-Infrared Radiation Drying on Starch Digestibility and the Content of Bioactive Compounds in Differently Pigmented Rice Varieties

Far infrared radiation (FIR) was applied to six rice varieties with different coloring of the pericarp (purple, red or non-pigment). Changes were determined in amylose content, in gelatinization parameters, in the content of bioactive compounds, in antioxidant activity and in the in vitro digestibility of pigmented rice as affected by FIR. The highest contents of amylose, total phenolic (TPC), total flavonoid (TFC) and total anthocyanins (TAC) were found in the purple and red varieties. Overall, FIR increased TPC, TFC and TAC, including antioxidant capacity. Quercetin and apigenin contents were increased while rutin and myricetin decreased significantly (p < 0.05) in all FIR-dried samples. Dephinidin, cyanidin-3-glucosides and pelargonidin increased after FIR treatment. Mostly, FIR-treated samples were found to have greater gelatinization enthalpy, compared with unheated rice samples. FIR-dried rice showed lower starch digestibility (25−40%) than unheated rice. This research suggested that the specific genotype of rice had the greatest influence on amylose content in pigmented rice, while FIR drying had no further effect. Our results suggest that FIR could enhance the content of the bioactive compounds capable of inhibiting α-amylase, thereby lowering starch digestibility. Hence, FIR may be considered as an appropriate drying method for pigmented rice regarding health benefits.

Involvement of Anthocyanin Biosynthesis of Cabernet Sauvignon Grape Skins in Response to Field Screening and In Vitro Culture Irradiating Infrared Radiation

To study the role of infrared (IR) radiation in the color change of the grape berry, field screening (IR-) and in vitro culture irradiation (IR+) were used. Acylated anthocyanin biosyntheses, including the biosynthesis of malvidin 3-O-glucoside, peonidin 3-O-glucoside, and their derivatives (acetylation and p-coumaroylation), were inhibited by IR-. IR+ promoted the biosynthesis of malvidin 3-O-glucoside and its derivatives, and IR+ inhibited the biosynthesis of peonidin 3-O-glucoside and its derivatives. WGCNA analysis revealed that the red module positively correlated with the flavonoid pathway. The hub genes were related to the anthocyanin pathway, including VvF3'5'H, VvANS, VvOMT1, VIT_18s0001g09400, and VvGST4. Further, the results revealed that transcription factors like RLK-Pelle, MYB, and C2H2 families were involved in response to IR radiation. Therefore, these results provide a complete understanding of IR radiation in grape skin color formation and the prospect of using supplemental light to improve the overall color of berries.

Bioactive Components in Whole Grains for the Regulation of Skeletal Muscle Function

Skeletal muscle plays a primary role in metabolic health and physical performance. Conversely, skeletal muscle dysfunctions such as muscular dystrophy, atrophy and aging-related sarcopenia could lead to frailty, decreased independence and increased risk of hospitalization. Dietary intervention has become an effective approach to improving muscle health and function. Evidence shows that whole grains possess multiple health benefits compared with refined grains. Importantly, there is growing evidence demonstrating that bioactive substances derived from whole grains such as polyphenols, γ-oryzanol, β-sitosterol, betaine, octacosanol, alkylresorcinols and β-glucan could contribute to enhancing myogenesis, muscle mass and metabolic function. In this review, we discuss the potential role of whole-grain-derived bioactive components in the regulation of muscle function, emphasizing the underlying mechanisms by which these compounds regulate muscle biology. This work will contribute toward increasing awareness of nutraceutical supplementation of whole grain functional ingredients for the prevention and treatment of muscle dysfunctions.

Thermal Control Using Far-Infrared Irradiation for Producing Deglycosylated Bioactive Compounds from Korean Ginseng Leaves

Although ginseng leaf is a good source of health-beneficial phytochemicals, such as polyphenols and ginsenosides, few studies have focused on the variation in compounds and bioactivities during leaf thermal processing. The efficiency of far-infrared irradiation (FIR) between 160 °C and 200 °C on the deglycosylation of bioactive compounds in ginseng leaves was analyzed. FIR treatment significantly increased the total polyphenol content (TPC) and kaempferol production from panasenoside conversion. The highest content or conversion ratio was observed at 180 °C (FIR-180). Major ginsenoside contents gradually decreased as the FIR temperature increased, while minor ginsenoside contents significantly increased. FIR exhibited high efficiency to produce dehydrated minor ginsenosides, of which F4, Rg6, Rh4, Rk3, Rk1, and Rg5 increased to their highest levels at FIR-190, by 278-, 149-, 176-, 275-, 64-, and 81-fold, respectively. Moreover, significantly increased antioxidant activities were also observed in FIR-treated leaves, particularly FIR-180, mainly due to the breakage of phenolic polymers to release antioxidants. These results suggest that FIR treatment is a rapid and efficient processing method for producing various health-beneficial bioactive compounds from ginseng leaves. After 30 min of treatment without leaf burning, FIR-190 was the optimum temperature for producing minor ginsenosides, whereas FIR-180 was the optimum temperature for producing polyphenols and kaempferol. In addition, the results suggested that the antioxidant benefits of ginseng leaves are mainly due to polyphenols rather than ginsenosides.

Effect of radiation processing on phenolic antioxidants in cereal and legume seeds: A review

Phenolic compounds in cereal and legume seeds show numerous benefits to human health mainly because of their good antioxidant capacity. However, long-term storage and some improper preservation may reduce their antioxidant potential. It is necessary to retain or modify the phenolic antioxidants with improved technology before consumption. Radiation processing is usually applied as a physical method to extend the shelf life and retain the quality of plant produce. However, the effect of radiation processing on phenolic antioxidants in cereal and legume seeds is still not well understood. This review summarizes recent research on the effect of radiation, including ionizing and nonionizing radiation on the content and profile of phenolic compounds, and antioxidant activities in cereal and legume seeds, the influencing factors and possible mechanisms are also discussed. The article will improve the understanding of radiation effect on phenolic antioxidants, and promote the radiation modification of natural phenolic compounds in cereal and legume seeds and other sources.

Widely Targeted Metabolomics Analysis of the Changes to Key Non-volatile Taste Components in Stropharia rugosoannulata Under Different Drying Methods

Stropharia rugosoannulata is an extremely perishable edible fungi product, and drying can delay its deterioration, however, drying will affect its flavor, especially the non-volatile taste substances dominated by amino acids, nucleotides, organic acids and carbohydrates. Currently, which drying method is the most suitable for the drying of S. rugosoannulata remains unknown, we need to fully consider the economic efficiency of the method and the impact on flavor. But we have limited comprehensive knowledge of the changed non-volatile taste metabolites as caused by drying processes. Here, an LC-MS/MS-based widely targeted metabolome analysis was conducted to investigate the transformation mechanism of S. rugosoannulata non-volatile taste components after undergoing hot air drying (HAD), vacuum freeze drying (VFD), and microwave vacuum drying (MVD). A total of 826 metabolites were identified, 89 of which—48 amino acids, 25 nucleotides, 8 organic acids, and 8 carbohydrates—were related to non-volatile taste. The drying method used and the parts of S. rugosoannulata (stipe and pileus) influenced the differences found in these metabolites. The possible mechanisms responsible for such chemical alterations by different drying methods were also investigated by a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Amino acid metabolism (alanine, aspartate, and glutamate metabolism; glycine, serine, and threonine metabolism; arginine and proline metabolism; valine, leucine, and isoleucine biosynthesis) was the main metabolic pathway involved. Pathway enrichment analysis also identified differences in non-volatile taste components among three drying methods that may be closely related to the applied drying temperature. Altogether, the results indicated that as an economical and convenient drying method, HAD is conducive to improving the flavor of S. rugosoannulata and thus it harbors promising potential for practical applications.

Enhancing drying efficiency and quality of seed-used pumpkin using ultrasound, freeze-thawing and blanching pretreatments

Effects of blanching (BL), ultrasound (US) and freeze-thawing (FT) pretreatments prior to far-infrared drying (FIRD) on drying characteristics, water distribution, and quality parameters of seed-used pumpkin (SUP) slices were investigated in this study. US, BL and FT pretreatments significantly accelerated drying rate due to the destruction of cell structure. Modified Page model was the fittest model for predicting the FIRD process. Low field nuclear magnetic resonance (LF-NMR) results revealed that T₂ distribution curves of all pretreated samples moved rapidly to the positive x-axis direction, indicating an increase in the rate of water migration. The color of US-FIRD was closer to fresh SUP. BL-FIRD exhibited the highest free polyphenols content (241.28 ± 1.11 mg GAE/100 g DW) and total carotenoids content (129.69 ± 2.49 μg/ g DW), increasing by 45% and 34% respectively compared to the untreated sample.

Drying methods influence the physicochemical and functional properties of seed-used pumpkin

The effects of far-infrared radiation drying (FIRD), freeze drying (FD), vacuum drying (VD), and hot air drying (HAD) on appearance, physicochemical properties, antioxidant activities, antityrosinase capacity using B16F10 melanoma cell from seed-used pumpkins (hull-less pumpkin and hull pumpkin) were evaluated. Results suggested that hull-less pumpkin (HLP) dehydrated by FIRD provided the highest total polyphenols content (37.11 ± 1.05 mg GAE/ g DW) and the ability of scavenging free radicals. HPLC analysis exhibited that coumaric acid was predominant phenolic acid in pumpkin. The correlation analysis demonstrated that polyphenolic compounds were related to antioxidant capacity. HLP-FD possessed better colour, higher preservation of β-carotene, ascorbic acid and higher sugar contents compared with HLP-HAD. The highest antityrosinase activity was recorded in HLP-VD with a concentration of 37.16%. The melanin inhibition increased to 76.61%, and intracellular tyrosinase activity in B16F10 melanoma cells decreased to 88.63% at 800 μg/mL of polyphenol extract.

Emerging drying techniques for food safety and quality: A review

The new trends in drying technology seek a promising alternative to synthetic preservatives to improve the shelf-life and storage stability of food products. On the other hand, the drying process can result in deformation and degradation of phytoconstituents due to their thermal sensitivity. The main purpose of this review is to give a general overview of common drying techniques with special attention to food industrial applications, focusing on recent advances to maintain the features of the active phytoconstituents and nutrients, and improve their release and storage stability. Furthermore, a drying technique that extends the shelf-life of food products by reducing trapped water, will negatively affect the spoilage of microorganisms and enzymes that are responsible for undesired chemical composition changes, but can protect beneficial microorganisms like probiotics. This paper also explores recent efficient improvements in drying technologies that produce high-quality and low-cost final products compared to conventional methods. However, despite the recent advances in drying technologies, hybrid drying (a combination of different drying techniques) and spray drying (drying with the help of encapsulation methods) are still promising techniques in food industries. In conclusion, spray drying encapsulation can improve the morphology and texture of dry materials, preserve natural components for a long time, and increase storage times (shelf-life). Optimizing a drying technique and using a suitable drying agent should also be a promising solution to preserve probiotic bacteria and antimicrobial compounds.

Multi-constituents variation in medicinal crops processing: Investigation of nine cycles of steam-sun drying as the processing method for the rhizome of Polygonatum cyrtonema

The rhizome of Polygonatum cyrtonema (Polygonati Rhizoma) is widely consumed as medicine-homology-food in Asia for its tonic effect, which can be enhanced by traditional steam-sun drying for nine cycles. However, the multi-constituents variation in this process was unclear, and the necessity of nine cycles should be further discussed. In this study, the multiple constituents, including saccharides, amino acids, nucleosides and bases, lipids, saponins, homoisoflavones and cinnamamides, in P. cyrtonema treated with sun drying, heated air drying, each cycle of steam-heated air drying, infrared drying and microwave drying were compared. The results showed that the content of total saccharides increased in samples from one to four cycles of steam-heated air drying (365.0-945.6 mg/g) and decreased from four to nine (945.6-288.0 mg/g). The content of fructose increased in samples from one to six cycles (29.9-234.7 mg/g) and decreased from six to nine (234.7-177.7 mg/g). The abundance of most phospholipids and free fatty acids increased continuously from one to nine cycles while most of the amino acids, nucleosides and bases showed continuous declining trend. Principal component analysis showed that the samples treated with one to four cycles were wider in distance than four to nine, indicating the chemical composition tending to be stable after fourth steaming. If taking total saccharides, fructose, and phospholipids as the major quality indicator, four cycles of steam-heated air drying processing should be the ideal postharvest processing method to obtain better taste, flavor and functionality. Samples treated with heated-air drying and infrared drying were far in distance from steaming ones by hierarchical cluster analysis, which means these processing methods were not suitable to replace the traditional steam-sun drying process. Collectively, the above results will not only provide novel processing methods that will obtain the high active ingredients for P. cyrtonema, but also shed light on the optimization of processing technology for the industrial production of medicinal crops which need nine cycles of steam-sun drying processing.

Drying Characteristics and Quality Attributes Affected by a Fluidized-Bed Drying Assisted with Swirling Compressed-Air for Preparing Instant Red Jasmine Rice

A new process for the production of instant red jasmine rice was investigated using fluidized bed drying with the aid of swirling compressed air. Drying characteristics were evaluated using the operating parameters of fluidizing air temperature (90–120 °C) and pressure of swirling compressed air (4–6 bar). Appropriate air pressure was determined based on the highest value of model parameters from the semi-empirical Page equation and effective diffusivity. Influences of supply time of swirling compressed air (2–10 min) and drying temperature of 90–120 °C were investigated and optimized based on the quality attributes using response surface methodology. Drying at 120 °C and compressed air pressure of 6 bar gave the highest rate constant and effective diffusion coefficient. Drying at 120 °C combined with injecting swirling air for 2 min was the most suitable approach, while drying at 90 °C and supplying compressed air for 10 min was the best choice to preserve antioxidant properties. Air temperature of 98.5 °C with 2 min supply of swirling compressed air suitably provided high physical and rehydration properties and retained high health benefits of antioxidant compounds. Finally, after rehydration in warm water at 70 °C for 10 min, the textural properties of the rehydrated rice sample were comparable to conventionally cooked rice.

Pressurized Hot Water Extraction of Okra Seeds Reveals Antioxidant, Antidiabetic and Vasoprotective Activities

Abelmoschus esculentus L. Moench (okra) is a commonly consumed vegetable that consists of the seeds and peel component which are rich in polyphenolic compounds. The aim of this study is to utilize pressurized hot water extraction (PHWE) for the extraction of bioactive phytochemicals from different parts of okra. A single step PHWE was performed at various temperatures (60 °C, 80 °C, 100 °C and 120 °C) to determine which extraction temperature exhibits the optimum phytochemical profile, antioxidant and antidiabetic activities. The optimum temperature for PHWE extraction was determined at 80 °C and the biological activities of the different parts of okra (Inner Skin, Outer Skin and Seeds) were characterized using antioxidant (DPPH and ABTS), α-glucosidase and vasoprotective assays. Using PHWE, the different parts of okra displayed distinct phytochemical profiles, which consist of primarily polyphenolic compounds. The okra Seeds were shown to have the most antioxidant capacity and antidiabetic effects compared to other okra parts, likely to be attributed to their higher levels of polyphenolic compounds. Similarly, okra Seeds also reduced vascular inflammation by downregulating TNFα-stimulated VCAM-1 and SELE expression. Furthermore, metabolite profiling by LC/MS also provided evidence of the cytoprotective effect of okra Seeds in endothelial cells. Therefore, the use of PHWE may be an alternative approach for the environmentally friendly extraction and evaluation of plant extracts for functional food applications.

The Potential of High-Anthocyanin Purple Rice as a Functional Ingredient in Human Health

Purple rice is recognized as a source of natural anthocyanin compounds among health-conscious consumers who employ rice as their staple food. Anthocyanin is one of the major antioxidant compounds that protect against the reactive oxygen species (ROS) that cause cellular damage in plants and animals, including humans. The physiological role of anthocyanin in plants is not fully understood, but the benefits to human health are apparent against both chronic and non-chronic diseases. This review focuses on anthocyanin synthesis and accumulation in the whole plant of purple rice, from cultivation to the processed end products. The anthocyanin content in purple rice varies due to many factors, including genotype, cultivation, and management as well as post-harvest processing. The cultivation method strongly influences anthocyanin content in rice plants; water conditions, light quantity and quality, and available nutrients in the soil are important factors, while the low stability of anthocyanins means that they can be dramatically degraded under high-temperature conditions. The application of purple rice anthocyanins has been developed in both functional food and other purposes. To maximize the benefits of purple rice to human health, understanding the factors influencing anthocyanin synthesis and accumulation during the entire process from cultivation to product development can be a path for success.

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.