Volatile Composition and Sensory Properties as Quality Attributes of Fresh and Dried Hemp Flowers (Cannabis sativa L.)

The influence of drying and storage conditions on the volatilome and cannabinoid content of Cannabis sativa L. inflorescences

The increasing interest in hemp and cannabis poses new questions about the influence of drying and storage conditions on the overall aroma and cannabinoids profile of these products. Cannabis inflorescences are subjected to drying shortly after harvest and then to storage in different containers. These steps may cause a process of rapid deterioration with consequent changes in precious secondary metabolite content, negatively impacting on the product quality and potency. In this context, in this work, the investigation of the effects of freeze vs tray drying and three storage conditions on the preservation of cannabis compounds has been performed. A multi-trait approach, combining both solid-phase microextraction (SPME) two-dimensional gas chromatography coupled to mass spectrometry (SPME-GC × GC-MS) and high-performance liquid chromatography (HPLC), is presented for the first time. This approach has permitted to obtain the detailed characterisation of the whole cannabis matrix in terms of volatile compounds and cannabinoids. Moreover, multivariate statistical analyses were performed on the obtained data, helping to show that freeze drying conditions is useful to preserve cannabinoid content, preventing decarboxylation of acid cannabinoids, but leads to a loss of volatile compounds which are responsible for the cannabis aroma. Furthermore, among storage conditions, storage in glass bottle seems more beneficial for the retention of the initial VOC profile compared to open to air dry tray and closed high-density polyethylene box. However, the glass bottle storage condition causes formation of neutral cannabinoids at the expenses of the highly priced acid forms. This work will contribute to help define optimal storage conditions useful to produce highly valuable and high-quality products.

Effect of High-Tunnel and Open-Field Production on the Yield, Cannabinoids, and Volatile Profiles in Industrial Hemp (Cannabis sativa L.) Inflorescence

This study discovered the impact of high-tunnel (i.e., unheated greenhouse) and open-field production on two industrial hemp cultivars (SB1 and CJ2) over their yield parameters, cannabinoid development, and volatile profiles. Development of neutral cannabinoids (CBD, THC, and CBC), acidic cannabinoids (CBDA, THCA, and CBCA), and total cannabinoids during floral maturation were investigated. The volatile profiles of hemp flowers were holistically compared via HS-SPME-GC/MS. Findings indicated a high tunnel as an efficient practice for achieving greater total weight, stem number, and caliper, especially in the SB1 cultivar. Harvesting high-tunnel-grown SB1 cultivars during early flower maturation could obtain a high CBD yield while complying with THC regulations. Considering the volatile profiles, hemp flowers mainly consisted of mono- and sesquiterpenoids, as well as oxygenated mono- and sesquiterpenoids. Volatile analysis revealed the substantial impact of cultivars on the volatile profile compared to the production systems.

Exploring the Nutritional Potential and Functionality of Hemp and Rapeseed Proteins: A Review on Unveiling Anti-Nutritional Factors, Bioactive Compounds, and Functional Attributes

Plant-based proteins, like those derived from hemp and rapeseed can contribute significantly to a balanced diet and meet human daily nutritional requirements by providing essential nutrients such as protein, fiber, vitamins, minerals, and antioxidants. According to numerous recent research papers, the consumption of plant-based proteins has been associated with numerous health benefits, including a reduced risk of chronic diseases such as heart disease, diabetes, and certain cancers. Plant-based diets are often lower in saturated fat and cholesterol and higher in fiber and phytonutrients, which can support overall health and well-being. Present research investigates the nutritional attributes, functional properties, and potential food applications of hemp and rapeseed protein for a potential use in new food-product development, with a certain focus on identifying anti-nutritional factors and bioactive compounds. Through comprehensive analysis, anti-nutritional factors and bioactive compounds were elucidated, shedding light on their impact on protein quality and digestibility. The study also delves into the functional properties of hemp and rapeseed protein, unveiling their versatility in various food applications. Insights from this research contribute to a deeper understanding of the nutritional value and functional potential of hemp and rapeseed protein, paving the way for their further utilization in innovative food products with enhanced nutritional value and notable health benefits.

In Pursuit of Optimal Quality: Cultivar-Specific Drying Approaches for Medicinal Cannabis

A limited number of studies have examined how drying conditions affect the cannabinoid and terpene content in cannabis inflorescences. In the present study, we evaluated the potential of controlled atmosphere drying chambers for drying medicinal cannabis inflorescence. Controlled atmosphere drying chambers were found to reduce the drying and curing time by at least 60% compared to traditional drying methods, while preserving the volatile terpene content. On the other hand, inflorescences subjected to traditional drying were highly infested by Alternaria alternata and also revealed low infestation of Botrytis cinerea. In the high-THC chemovar ("240"), controlled N2 and atm drying conditions preserved THCA concentration as compared to the initial time point (t0). On the other hand, in the hybrid chemovar ("Gen12") all of the employed drying conditions preserved THCA and CBDA content. The optimal drying conditions for preserving monoterpenes and sesquiterpenes in both chemovars were C5O5 (5% CO2, 5% O2, and 90% N2) and pure N2, respectively. The results of this study suggest that each chemovar may require tailored drying conditions in order to preserve specific terpenes and cannabinoids. Controlled atmosphere drying chambers could offer a cost-effective, fast, and efficient drying method for preserving cannabinoids and terpenes during the drying process while reducing the risk of mold growth.

Solid-State Microwave Drying for Medical Cannabis Inflorescences: A Rapid and Controlled Alternative to Traditional Drying

Introduction: As the medical use of Cannabis is evolving there is a greater demand for high-quality products for patients. One of the main steps in the manufacturing process of medical Cannabis is drying. Most current drying methods in the Cannabis industry are relatively slow and inefficient processes. Materials and Methods: This article presents a drying method based on solid-state microwave (MW) that provides fast and uniform drying, and examines its efficiency for drying Cannabis inflorescences compared with the traditional drying method. We assessed 67 cannabinoids and 36 terpenoids in the plant in a range of drying temperatures (40°C, 50°C, 60°C, and 80°C). The identification and quantification of these secondary metabolites were done by chromatography methods. Results: This method resulted in a considerable reduction of drying time, from several days to a few hours. The multiple frequency-phase combination states of the system allowed control and prediction of moisture levels during drying, thus preventing overdrying. A drying temperature of 50°C provided the most effective results in terms of both short drying time and preservation of the composition of the secondary metabolites compared with traditional drying. At 50°C, the chemical profile of phytocannabinoids and terpenoids was best kept to that of the original plant before drying, suggesting less degradation by chemical reactions such as decarboxylation. The fast-drying time also reduced the susceptibility of the plant to microbial contamination. Conclusion: Our results support solid-state MW drying as an effective postharvest step to quickly dry the plant material for improved downstream processing with a minimal negative impact on product quality.

Sesquiterpene-evoked phytochemical toxicity in PC12 neuronal cells reveals a variable degree of oxidative stress and alpha-tocopherol and glutathione-dependent protection

Phytochemicals are often promoted generally as antioxidants and demonstrate variable levels of reactive oxygen species (ROS) sequestration in vitro, which attributes to their neuroprotective bioactivity. Sesquiterpenes from cannabis and essential oils may demonstrate bifunctional properties towards cellular oxidative stress, possessing pro-oxidant activities by generating ROS or scavenging ROS directly. Sesquiterpenes can also oxidize forming sesquiterpene oxides, however the relative contribution they make to the bioactivity or cytotoxicity of complex botanical extracts more generally is unclear, while selected cannabis-prevalent terpenes such as β-caryophyllene may also activate cannabinoid receptors as part of their biological activity. In the present study, we investigated selected sesquiterpenes β-caryophyllene and humulene and their oxidized forms (β-caryophyllene oxide and zerumbone, respectively) against established antioxidants (ascorbic acid, α-tocopherol, and glutathione) and in the presence of cannabinoid receptor 1 and cannabinoid receptor 2 antagonists, to gain a better understanding of the molecular and cellular mechanisms of neuroprotection versus neurotoxicity in semi-differentiated rat neuronal phaeochromocytoma (PC12) cells. Our results demonstrate that the sesquiterpenes β-caryophyllene, humulene and zerumbone possess concentration-dependent neurotoxic effects in PC12 cells. Both β-caryophyllene- and humulene-evoked toxicity was unaffected by CB1 or CB2 receptor antagonism, demonstrating this occurred independently of cannabinoid receptors. Both glutathione and α-tocopherol were variably able to alleviate the concentration-dependent loss of PC12 cell viability from exposure to β-caryophyllene, humulene and zerumbone. During 4-hour exposure to sesquiterpenes only modest increases in ROS levels were noted in PC12 cells, with glutathione co-incubation significantly inhibiting intracellular ROS production. However, significant increases in ROS levels in PC12 cells were demonstrated during 24-hour incubation with either antioxidants or sesquiterpenes individually, and with additive toxicity exhibited in combination. Overall, the results highlight a concentration-dependent profile of sesquiterpene neurotoxicity independent of cannabinoid receptors and dissociated from the formation of reactive oxygen species as a marker or correlate to the loss of cell viability.

Effect of Drying Methods on Chemical and Sensory Properties of Cannabis sativa Leaves

Hemp is used as a source of fiber, oil and bioactive substances including volatile and cannabinoid-containing substances. This paper presents, for the first time, results on the evaluation of drying methods (convective, vacuum-microwave and combined convective pre-drying and vacuum-microwave finishing drying) of hemp leaves on the qualitative and quantitative changes in secondary metabolites, including essential oils, cannabinoids and sterols. A ranking and descriptive test of hemp leaves was also performed. Drying kinetics was presented using three models, including logarithmic, Midilli and modified Page. The SPME-Arrow technique was used to determine 41 volatile compounds, of which caryophyllene, β-myrcene and α-humulene were dominant in dried and fresh leaves. Regarding the essential oils obtained, 64 were identified, with caryophyllene, humulene epoxide II and limonene being the dominant ones. For preserving the highest amount of oils, the best method was the convective pre-drying followed by vacuum-microwave finishing drying (CD60-VMD) combined method, where the retention of volatile compounds was 36.08%, whereas the CD70 and 240-VMD methods resulted in the highest loss of 83%. The predominant cannabinoids in fresh hemp leaves were CBDA 6.05 and CBD 2.19 mg g-1. Drying caused no change in the cannabinoid profile of the plant material. β-Sitosterol, campesterol and lupeol were dominant in the phytosterol and triterpene fractions. No changes in either quality or quantity were observed in any of the variants found.

The Antioxidant and Neuroprotective Potential of Leaves and Inflorescences Extracts of Selected Hemp Varieties Obtained with scCO2

Cannabis sativa, a versatile plant with numerous varieties, holds promising potential for a wide range of biological activity. As raw materials for research, we chose leaves and inflorescences of hemp varieties such as Białobrzeskie, Henola, and Tygra, which are cultivated mainly for their fibers or seeds. The choice of extraction is a key step in obtaining the selected compositions of active compounds from plant material. Bearing in mind the lipophilic nature of cannabinoids, we performed supercritical carbon dioxide (scCO2) extraction at 50 °C under 2000 (a) and 6000 PSI (b). The cannabinoid contents were determined with the use of the HPLC-DAD method. The antioxidant capabilities were assessed through a series of procedures, including the DPPH, ABTS, CUPRAC, and FRAP methods. The capacity to inhibit enzymes that play a role in the progression of neurodegenerative diseases, such as acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase was also studied. The dominant cannabinoids in the extracts were cannabidiol (CBD) and cannabidiolic acid (CBDA). The highest concentration of eight cannabinoids was detected in the Tygra inflorescences extract (b). The most notable antioxidant properties were provided by the Tygra inflorescences extract (b). Nonetheless, it was the Henola inflorescences extract (b) that demonstrated the most efficient inhibition of AChE and BChE, and tyrosinase was inhibited the most significantly by the Białobrzeskie inflorescences extract (b). Multidimensional comparative analysis enrolled all assays and revealed that the Henola inflorescences extract (b) showed the most substantial neuroprotective potential.

The Role of Hemp (Cannabis sativa L.) as a Functional Food in Vegetarian Nutrition

Recently, there has been a renewed interest in Cannabis sativa and its uses. The recreational use of inflorescences as a source of THC has led to the legal restriction of C. sativa cultivation to limit the detrimental effects of psychotropic substance abuse on health. However, this has also limited the cultivation of textile/industrial varieties with a low content of THC used for textile and nutritional purposes. While previously the bans had significantly penalized the cultivation of C. sativa, today many countries discriminate between recreational use (marijuana) and industrial and food use (hemp). The stalks of industrial hemp (low in psychotropic substances) have been used extensively for textile purposes while the seeds are nutritionally versatile. From hemp seeds, it is possible to obtain flours applicable in the bakery sector, oils rich in essential fatty acids, proteins with a high biological value and derivatives for fortification, supplementation and nutraceutical purposes. Hemp seed properties seem relevant for vegetarian diets, due to their high nutritional value and underestimated employment in the food sector. Hemp seed and their derivatives are a valuable source of protein, essential fatty acids and minerals that could provide additional benefit to vegetarian nutrition. This document aims to explore the information available in the literature about hemp seeds from a nutritional point of view, highlighting possible beneficial effects for humans with particular attention to vegetarian nutrition as a supplemental option for a well-planned diet.

The Effect of Nonthermal Pretreatment on the Drying Kinetics and Quality of Black Garlic

Black garlic is obtained from regular garlic (Allium sativum L.) through the aging process and consequently gains many health-promoting properties, including antidiabetic and antioxidant. However, the material is still prone to microbiological deterioration and requires a long time to dry due to its properties. Therefore, this study aimed to investigate the effect of various drying methods on the quality of black garlic as well as determine the influence of selected nonthermal pretreatments on the drying kinetics and quality of black garlic, which is especially important in the case of the materials that are difficult to dry. The Weibull model was chosen to describe drying kinetics. Additionally, color, water activity together with antioxidant activity, phenolic compounds, and antidiabetic potential were determined. This study found that the application of a pulsed electric field (PEF), a constant electric field (CEF) as well as a magnetic field (MF) significantly reduced the time of drying (by 32, 40, and 24 min for a PEF, a CEF, and a MF, respectively, compared to combined drying without the pretreatment), and resulted in high antidiabetic potential. However, the highest content of phenolic compounds (1123.54 and 1125.36 mg/100 g dm for VMD125 and CD3h-VMD, respectively) and antioxidant capacity (ABTS = 6.05 and 5.06 mmol Trolox/100 g dm for VMD500 and CD6h-VMD, respectively) were reported for black garlic treated by vacuum-microwave drying and combined convective pre-drying followed by vacuum-microwave drying. Overall, the nonthermal pretreatment decreased the time of drying and showed very good efficiency in maintaining the antidiabetic potential of black garlic, especially in the case of the materials pretreated by a constant electric field (IC₅₀ = 99 and 56 mg/mL, for α-amylase and α-glucosidase, respectively).

Evaluating Cannabis sativa L.'s neuroprotection potential: From bench to bedside

BACKGROUND

Neurodegenerative diseases and dementia pose a global health challenge in an aging population, exemplified by the increasing incidence and prevalence of its most common form, Alzheimer's disease. Although several approved treatments exist for Alzheimer's disease, they only afford transient symptomatic improvements and are not considered disease-modifying. The psychoactive properties of Cannabis sativa L. have been recognized for thousands of years and now with burgeoning access to medicinal formulations globally, research has turned to re-evaluate cannabis and its myriad phytochemicals as a potential treatment and adjunctive agent for neurodegenerative diseases.

PURPOSE

This review evaluated the neuroprotective potential of C. sativa's active constituents for potential therapeutic use in dementia and Alzheimer's disease, based on published studies demonstrating efficacy in experimental preclinical settings associated with neurodegeneration.

STUDY DESIGN

Relevant information on the neuroprotective potential of the C. sativa's phytoconstituents in preclinical studies (in vitro, in vivo) were included. The collated information on C. sativa's component bioactivity was organized for therapeutic applications against neurodegenerative diseases.

METHODS

The therapeutic use of C. sativa related to Alzheimer's disease relative to known phytocannabinoids and other phytochemical constituents were derived from online databases, including PubMed, Elsevier, The Plant List (TPL, www.theplantlist.org), Science Direct, as well as relevant information on the known pharmacological actions of the listed phytochemicals.

RESULTS

Numerous C. sativa -prevalent phytochemicals were evidenced in the body of literature as having efficacy in the treatment of neurodegenerative conditions exemplified by Alzheimer's disease. Several phytocannabinoids, terpenes and select flavonoids demonstrated neuroprotection through a myriad of cellular and molecular pathways, including cannabinoid receptor-mediated, antioxidant and direct anti-aggregatory actions against the pathological toxic hallmark protein in Alzheimer's disease, amyloid β.

CONCLUSIONS

These findings provide strong evidence for a role of cannabis constituents, individually or in combination, as potential neuroprotectants timely to the emergent use of medicinal cannabis as a novel treatment for neurodegenerative diseases. Future randomized and controlled clinical studies are required to substantiate the bioactivities of phytocannabinoids and terpenes and their likely synergies.

Cannabis sativa Cannabinoids as Functional Ingredients in Snack Foods-Historical and Developmental Aspects

The published health benefits of Cannabis sativa has caught the attention of health-conscious consumers and the food industry. Historically, seeds have long been utilized as a food source and currently there is an increasing number of edibles on the market that contain cannabis. Cannabinoids include the psychoactive constituent, delta-9-tetrahydrocannabinol (THC), and the non-psychoactive cannabidiol (CBD) that are both compounds of interest in Cannabis sativa. This paper looks at the distribution of nutrients and phytocannabinoids in low-THC Cannabis sativa, the historical uses of hemp, cannabis edibles, and the possible side-effects and concerns related to cannabis edibles. Several authors have pointed out that even though the use of cannabis edibles is considered safe, it is important to mention their possible side-effects and any concerns related to its consumption that negatively influence consumer acceptance of cannabis edibles. Such risks include unintentional overdose by adults and accidental ingestion by children and adolescents resulting in serious adverse effects. Therefore, cannabis edibles should be specifically packaged and labelled to differentiate them from known similar non-cannabis edibles so that, together with tamperproof packaging, these measures reduce the appeal of these products to children.

Uncovering the secrets of industrial hemp in food and nutrition: The trends, challenges, and new-age perspectives

Hemp is a valuable crop with a wide range of use, from applications in foods and textiles to pharmaceuticals. Over recent years, the use of hemp as food and food ingredients has drastically increased. The growth is driven by numerous health benefits hemp possesses and its wide range of applications in the food industry. This review provides the scientific literature concerning the benefits of industrial hemp in the food industry. The relevant historical context of use, recent applications in the food industry, health benefits, various development challenges, and the global market outlook for hemp-based food products have been analyzed. Evidence suggests that today hemp is widely consumed as food or an ingredient in the food. Hemp-based foods are marketed as having various health benefits, although their reception by target consumers and success varies. Besides, scientific research on hemp-derived foods has dramatically increased over recent years. Numerous in vitro and in vivo studies have investigated the health benefits of hemp-based foods. Therefore, there is a promising growth trend in producing novel foods from industrial hemp. Nevertheless, due to health concerns related to THC, there is a general need for regulatory compliance when integrating hemp into foods to ensure product safety before use.

Chemical investigation on Salvia officinalis L. Affected by multiple drying techniques - The comprehensive analytical approach (HS-SPME, GC-MS, LC-MS/MS, GC-O and NMR)

In light of large scale production of Salvia officinalis L. and its complex storage and delivery chain, the efficient preservation process is required. At this moment, the most popular preservation method is drying, therefore a comprehensive experiment to evaluate the influence of multiple drying techniques on sage was conducted. Convective drying at 40, 50 and 60 °C, vacuum-microwave drying with powers 240, 360 and 480 W and combined drying consisting of convective pre-drying at 50 °C followed by vacuum-microwave finish-drying with power 360 W were applied. To evaluate the effect of particular procedures chemical analyses were performed, namely evaluation of changes in bioactive volatile constituents, odour-active compounds and various groups of non-volatile bioactive constituents of sage. The obtained results shown, that to receive the product with expected quality, it is necessary to identify the designation of the product before treatment, since particular groups of phytochemicals react differently during drying.

Post-Harvest Operations to Generate High-Quality Medicinal Cannabis Products: A Systemic Review

The traditional Cannabis plant as a medicinal crop has been explored for many thousands of years. The Cannabis industry is rapidly growing; therefore, optimising drying methods and producing high-quality medical products have been a hot topic in recent years. We systemically analysed the current literature and drew a critical summary of the drying methods implemented thus far to preserve the quality of bioactive compounds from medicinal Cannabis. Different drying techniques have been one of the focal points during the post-harvesting operations, as drying preserves these Cannabis products with increased shelf life. We followed or even highlighted the most popular methods used. Drying methods have advanced from traditional hot air and oven drying methods to microwave-assisted hot air drying or freeze-drying. In this review, traditional and modern drying technologies are reviewed. Each technology will have different pros and cons of its own. Moreover, this review outlines the quality of the Cannabis plant component harvested plays a major role in drying efficiency and preserving the chemical constituents. The emergence of medical Cannabis, and cannabinoid research requires optimal post-harvesting processes for different Cannabis strains. We proposed the most suitable method for drying medicinal Cannabis to produce consistent, reliable and potent medicinal Cannabis. In addition, drying temperature, rate of drying, mode and storage conditions after drying influenced the Cannabis component retention and quality.

Influence of Technological Maturity on the Secondary Metabolites of Hemp Concentrate (Cannabis sativa L.)

During the last decade, the popularity of hemp products has been rising rapidly. Products containing cannabidiol (CBD) are of predominant interest. Traditional hemp products are frequently enriched by CBD due to their potential therapeutic effects. Cannabidiol occurs naturally in hemp juice together with other biologically active substances, such as terpenes, flavonoids, and stilbenoids. These constituents act synergistically. This study aimed to observe the influence of the hemp plant developmental stage on its chemical composition and antioxidant activity. The hemp plants were analyzed during three vegetative stages, i.e., before, during, and after flowering. The collected samples were evaluated using the following analyses: total polyphenolic content and profile, terpenoid and cannabinoid contents, and ferric reducing antioxidant power. The results revealed statistically significant differences between the samples in almost all set parameters. The optimal period for hemp harvest depends on desirable compounds, i.e., phenolic content is the highest before flowering, while the levels of cannabinoids and terpenoids are the highest during the flowering period.

Extraction of Phenolic Compounds and Terpenes from Cannabis sativa L. By-Products: From Conventional to Intensified Processes

Cannabis sativa L. is a controversial crop due to its high tetrahydrocannabinol content varieties; however, the hemp varieties get an increased interest. This paper describes (i) the main categories of phenolic compounds (flavonoids, stilbenoids and lignans) and terpenes (monoterpenes and sesquiterpenes) from C. sativa by-products and their biological activities and (ii) the main extraction techniques for their recovery. It includes not only common techniques such as conventional solvent extraction, and hydrodistillation, but also intensification and emerging techniques such as ultrasound-assisted extraction or supercritical CO₂ extraction. The effect of the operating conditions on the yield and composition of these categories of phenolic compounds and terpenes was discussed. A thorough investigation of innovative extraction techniques is indeed crucial for the extraction of phenolic compounds and terpenes from cannabis toward a sustainable industrial valorization of the whole plant.

Impact of Preharvest and Postharvest on Color Changes during Convective Drying of Mangoes

The purpose of this study was to evaluate the impact of the harvest stage, ripening conditions and maturity on color changes of cv. ‘Cogshall’ and cv. ‘Kent’ variety mangoes during drying. A total of four harvests were undertaken, and the fruits were ripened at 20 and 35 °C for five different ripening times at each temperature. At each ripening time, mangoes were dried at 60 °C/30% RH/1.5 m/s for 5 h. A wide physico-chemical and color variability of fresh and dry pulp was created. The relationships according to the L*, H* and C* coordinates were established using mixed covariance regression models in relation to the above pre- and postharvest (preprocess) parameters. According to the L* coordinate results, browning during drying was not affected by the preprocess parameters. However, dried slices from mangoes ripened at 35 °C exhibited better retention of the initial chroma, and had a greater decrease in hue than dried slices from mangoes ripened at 20 °C. However, fresh mango color, successfully managed by the pre- and postharvest conditions, had more impact on dried mango color than the studied parameters. The preprocess parameters were effective levers for improving fresh mango color, and consequently dried mango color.

Flavor and Aroma Analysis as a Tool for Quality Control of Foods

The aroma composition of foods has been the subject of considerable research in recent years [...].

Comparison of Traditional and Novel Drying Techniques and Its Effect on Quality of Fruits, Vegetables and Aromatic Herbs

Drying is known as the best method to preserve fruits, vegetables, and herbs, decreasing not only the raw material volume but also its weight. This results in cheaper transportation and increments the product shelf life, limiting the food waste. Drying involves the application of energy in order to vaporize and mobilize the moisture content within the porous products. During this process, the heat and mass transfer occurs simultaneously. The quality of dehydrated fruits, vegetables, and aromatic herbs is a key problem closely related to the development and optimization of novel drying techniques. This review reports the weaknesses of common drying methods applied for fruits, vegetables, and aromatic herbs and the possible options to improve the quality of dried products using different drying techniques or their combination. The quality parameters under study include color, bulk density, porosity, shrinkage, phytochemicals, antioxidant capacity, sugars, proteins, volatile compounds, and sensory attributes. In general, drying leads to reduction in all studied parameters. However, the behavior of each plant material is different. On the whole, the optimal drying technique is different for each of the materials studied and specific conditions must be recommended after a proper evaluation of the drying protocols. However, a novel or combined technique must assure a high quality of dried products. Furthermore, the term quality must englobe the energy efficiency and the environmental impact leading to production of sustainable dried products.