Effect of drying method on the antioxidant capacity of six Lamiaceae herbs

The occurrence of aflatoxins and labelling compliance of locally produced za'atar mix products

Za'atar mix products are mainly composed of the dried and ground leaves and/or blossoms of wild and cultivated plant species (Origanum, Thymbra, Thymus, and Satureja) with the addition of condiments. The aim of this study was to evaluate the occurrence of aflatoxins, chemical composition (carbohydrates, fibre, fat, protein, moisture, ash, and acid contents), mineral content (Na, Ca, and K), and colour traits (L*a*b*) in relation to food label and food standards compliance. Measured and labelled fat content did not agree for approximately 91% of the samples. There was also no agreement between the measured and labelled fibre contents. The total content of aflatoxins in the tested samples ranged from 2 to 63.7 ng g-1. Eleven (69%) of the 16 analysed products had total aflatoxins higher than the maximum permitted limit of the European Commission. The KAS and LAZ products had significantly lighter colour (the highest L* values), while the ALAQ product had the darkest colour (lowest L* value). The range of sodium content in the tested products was 105.1-1425.3 mg/100 g. In conclusion, za'atar mix products that are available in local markets do not have accurate nutritional labelling information, and the occurrence of aflatoxins was very high. Further studies are needed to evaluate the reasons for these quality defects.

Effect of gamma rays on the essential oil and biochemical characteristics of the Satureja mutica Fisch & C. A. Mey

There are 16 species in the genus Satureja L. (Lamiaceae), of which 10 are native. This research aimed to investigate the effect of gamma rays and storage conditions and duration on the percentage and components of the essential oil and some biochemical characteristics of Satureja mutica Fisch & C.A. Mey at the Research Institute of Forests and Rangelands. Plants were collected at the full flowering stage and exposed to different doses of gamma rays (0, 2.5, 5, 7.5, and 10 kGy) at the Atomic Energy Organization, Iran. The samples were kept in a refrigerator (4 °C) and in the shade (25 ± 2 °C) for 0, 120, and 240 h. This experiment was performed in a completely randomized design. Essential oil extraction was done by water distillation for 2 h. The composition of their essential oil components was identified using GC and GC/MS. Some biochemical traits, including phenol content, antioxidant capacity, and carbohydrate content, were measured. The results indicated that irradiation on the percentage of essential oil showed a statistically significant difference. In addition, the interaction effect of irradiation × storage conditions, irradiation × duration of storage, on the percentage of essential oil was significant. According to a comparison of the means, 2.5 kGy irradiation produced the highest percentage of essential oil (0.4%); in contrast, a significant decrease was detected in components with 7.5 and 10 kGy irradiation. It was observed that the percentage of some essential oil compounds decreased with the gamma-ray intensity increase. 2.5 kGy of gamma rays and shade storage conditions for 240 h led to the highest content of p-cymene and carvacrol. Nevertheless, the highest thymol content was obtained under refrigeration conditions without irradiation. The maximum phenol content and antioxidant capacity were obtained when the plants were irradiated with 2.5 and 7.5 kGy gamma rays. However, the maximum carbohydrate rate was observed in non-irradiated plants. It was concluded that low-intensity gamma rays could improve the percentage of essential oil and main components like p-cymene and carvacrol in S. mutica Fisch & C.A. Mey.

Quality Characteristics of Raspberry Fruits from Dormancy Plants and Their Feasibility as Food Ingredients

The raspberry (Rubus idaeus L.) is a soft red fruit consumed worldwide due to its bitter-sweet taste and phenolics-associated health benefits. During plant dormancy, raspberry fruits are discarded. However, this work hypothesised that these fruits have the chemical quality to be valorised, which would mitigate their waste if adequately stabilised. This can be achieved by drying. The Pacific Deluxe and Versailles varieties were dried by freeze- and convective-drying (30 °C and 40 °C). The freeze-dried fruits preserved their colour, drupelets structure, and phenolic content. Convective-drying promoted a significant fruit darkening, which was more evident at 30 °C due to the longer drying process, and a loss of drupelets structure. Both temperatures promoted a similar decrease in phenolic content, as determined by HPLC, although the ABTS●+ antioxidant activity at 40 °C was lower (IC50 = 9 compared to 13 μg AAE/mg dry weight). To incorporate dried raspberries into muffin formulations, while keeping their red colour, it was necessary to change the raising agent from sodium bicarbonate to baker's yeast. Sensory analysis by a non-trained panel revealed good acceptance, showing that fresh or dried raspberry fruits from dormancy had suitable characteristics for use as food ingredients.

Effect of Drying and Freezing on the Phytochemical Properties of Okra during Storage

Okra (Abelmoschus esculentus L.) is known for its high nutritional value, including its content of phytochemicals. This study aims to investigate the effect of drying and freezing conditions on the phytochemical content of okra. Our results indicated that both air-drying and freezing okra during 6 months of storage showed a significant decrease in total phenolic content, flavonoid content, anthocyanin content, and antioxidant activity. Furthermore, higher levels of phytochemicals were found for okra samples treated with Na2SO4 solution when compared to untreated okra. The freezing process appeared to better preserve the content of the investigated phytochemicals when compared to the decrease after drying. Our research has determined that both immersing and freezing okra samples consistently yielded better results in the preservation of phytochemical properties over time, compared to other methods. This study is important for the food industry, as it highlights the importance of proper storage methods to retain the nutritional value of okra.

Effects of pretreatment methods on the physicochemical properties of dried longan (Dimocarpus longan Lour.) pulps

Several pretreatment methods were used before hot air drying to determine the effects of pretreatment on the physicochemical properties of dried longan pulps to address issues of low efficiency and excessive browning of pulps in dried longan. The results showed that pretreatment methods such as sodium chloride steeping, hot blanching, and freeze-thawing reduced the moisture content in dried longan pulps and increased the hardness of dried longan pulps. Ultrasound, microwave, and hot blanching methods reduced the degree of browning of dried longan pulps. Freeze thawing led to a decrease in polysaccharide content in dried longan pulps. The use of ultrasound- and microwave-based pretreatment methods increased the contents of free phenolics and total phenolics and increased the oxygen radical absorbance capacity indices. Alkenes and alcohols constituted the primary volatile flavor substances in longan. It was inferred that it was favorable to use the hot blanching method before subjecting the samples to conditions of hot air drying as the moisture content and degree of browning could be reduced effectively. The results reported herein can potentially help manufacturers improve drying efficiency. The results provide a platform to produce high-quality products from dried longan pulps. PRACTICAL APPLICATION: Longan pulps should be subjected to conditions of the hot blanching method before subjecting the samples to conditions of hot air drying to reduce the moisture content and degree of browning. The results reported herein can help manufacturers improve the drying efficiency of pulps. The results can be exploited to produce high-quality products from dried longan pulps.

Bioefficacy of Nga-Mon (Perilla frutescens) Fresh and Dry Leaf: Assessment of Antioxidant, Antimutagenicity, and Anti-Inflammatory Potential

Perilla leaves are known to be a rich source of polyphenols, which have been shown to exhibit various biological effects. This study aimed to compare the bioefficacies and bioactivities of fresh (PLE_f) and dry (PLE_d) Thai perilla (Nga-mon) leaf extracts. Phytochemical analysis indicated that both PLE_f and PLE_d were abundant in rosmarinic acid and bioactive phenolic compounds. PLE_d, which had higher levels of rosmarinic acid but lower levels of ferulic acid and luteolin than PLE_f, exhibited greater effectiveness in a free radical scavenging assay. Furthermore, both extracts were found to suppress intracellular ROS generation and exhibit antimutagenic activity against food-borne carcinogens in S. typhimurium. They also attenuated lipopolysaccharide-induced inflammation in RAW 264.7 cells by inhibiting the expression of nitric oxide, iNOS, COX-2, TNF-α, IL-1β, and IL-6 through the suppression of NF-κB activation and translocation. However, PLE_f exhibited a higher ability to suppress cellular ROS production and higher antimutagenic and anti-inflammatory activities than PLE_d, which can be attributed to its combination of phytochemical components. Overall, PLE_f and PLE_d have the potential to serve as natural bioactive antioxidant, antimutagenic, and anti-inflammatory agents to achieve potential health benefits.

Differentiation of Medicinal Plants According to Solvents, Processing, Origin, and Season by Means of Multivariate Analysis of Spectroscopic and Liquid Chromatography Data

Effects of processing and extraction solvents on antioxidant properties and other characteristics were evaluated for ten medicinal plant species originating from two different localities and two production years. A combination of spectroscopic and liquid chromatography techniques possessed data for multivariate statistics. Water, 50% (v/v) ethanol, and dimethyl sulfoxide (DMSO) were compared to select the most suitable solvent for the isolation of functional components from the frozen/dried medicinal plants. DMSO and 50% (v/v) ethanol were evaluated as more efficient for phenolic compounds and colorants extraction, while water was more useful for element extraction. Drying and extraction of herbs with 50% (v/v) ethanol was the most appropriate treatment to ensure a high yield of most compounds. The satisfactory differentiation of herbs (61.8-100%) confirmed the significant effect of the processing, geographical, and seasonal factors on target functional component concentrations. Total phenolic and total flavonoid compounds content, total antioxidant activity expressed as TAA, yellowness, chroma, and browning index were identified as the most important markers for medicinal plant differentiation.

Updated Organic Composition and Potential Therapeutic Properties of Different Varieties of Olive Leaves from Olea europaea

Olea europaea L. folium merits further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of Madural, Verdeal, and Cobrançosa elementary leaves and leaf sprouts (mamões) collected in the region of Valpaços, Portugal. Organic analysis assessed the moisture content, total carbohydrates, ash, protein, and fat contents, total phenolic content (TPC), vitamin E, and fatty acid (FA) profiles. Moisture content was determined through infrared hygrometry and TPC was determined by a spectrophotometric method. Concerning organic analysis, all leaf samples showed similar moisture content, though Cobrançosa's leaf sprouts and Verdeal's elementary leaves had slightly lower contents. Meanwhile, these cultivars also showed a higher TPC, α-tocopherol isomer, and fatty acid composition (FAC). FAC in all samples exhibited higher contents of PUFA and SFA than MUFA, with a predominance of linolenic and palmitic acids. Organic analyses of Cobrançosa's leaf sprouts and Verdeal's elementary leaf extracts allow for the prediction of adequate physiological properties regarding neuroinflammatory, neurobehavioral, metabolic, cardiovascular, osteo-degenerative, anti-ageing, pulmonary, and immunological defense disorders. These physiological changes observed in our preliminary in silico studies suggest an excellent nutraceutical, which should be borne in mind during severe pandemic situations.

Chemical composition and antinociceptive and anti-inflammatory activity of the essential oil of Hyptis crenata Pohl ex Benth. from the Brazilian Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

The leaf tea of Hyptis crenata has its practical use in the Brazilian Amazon for treating gastrointestinal and liver disorders, sweating induction, and as an anti-inflammatory.

AIM OF THE STUDY

Evaluation of the chemical composition, acute oral toxicity, and antinociceptive and anti-inflammatory activities of the H. crenata essential oil.

MATERIAL AND METHODS

The essential oil was hydrodistilled and analyzed by GC and GC-MS. The antinociceptive action in mice was evaluated for the peripheral and central analgesic activity (abdominal contortion and hot plate tests), and the xylene-induced ear swelling was carried out for the nociception test.

RESULTS

Oxygenated monoterpenes (53.0%) and monoterpene hydrocarbons (38.9%) predominated in the H. crenata oil, being 1,8-cineo1e (35.9%), α-pinene (20.8%), camphor (10.0%), and β-pinene (7.3%) their primary constituents. The oral oil administration in the mice did not display changes in behavior patterns or animal mortality at 300 and 2000 mg/kg doses. The control group's biochemical parameters (ALP, AST, ALT) displayed a statistical difference from the treated group, unlike the renal parameters, which showed no variation between the groups. Oil reduced the abdominal contortions at doses of 100 (79.5%) and 300 mg/kg (44.4%), while with endodontacin, the dose was 5 mg/kg (75.2%). In addition, the oil could not decrease the paw licking/biting time at doses of 30, 100, and 300 mg/kg. However, it showed a significant antinociceptive effect on the second phase in the formalin test inhibiting licking time, with a reduction of 50.8% (30 mg/kg), 63.4% (100 mg/kg), 58.0% (300 mg/kg), and morphine (4 mg/kg, 78.3%). The oil administration produced significant inhibition of ear edema at all tested doses, with a better effect produced at 30 mg/kg (64.0% inhibition).

CONCLUSION

The oil of Hyptis crenata, rich in 1,8-cineole, camphor, α-pinene, and β-pinene, totaling 74%, displayed low acute toxicity and significant anti-inflammatory activity, with peripheral and no central antinociceptive action. Thus, these results show an actual perspective on using H. crenata oil in developing a phytotherapeutic product.

Antioxidant Properties of Dried Ginger (Zingiber officinale Roscoe) var. Bentong

Ginger (Zingiber officinale Roscoe) is a popular culinary herb used in the Eastern culture. The essential cultivar of the Zingiber genus is rich in antioxidants and is crucial in the fight against oxidative stress-related diseases. The antioxidant properties of dried ginger were evaluated and compared for their efficacy from different drying processes (sun-, oven-, vacuum- and freeze-drying) and using three extraction solvents: hot water, aqueous ethanol (80%, v/v) and ethanol. The drying process demonstrated a positive effect on the antioxidant activities of ginger. A significant difference (p < 0.05) was observed in the extracting ability of each solvent. Sun-dried ginger extracted with ethanol performed better than the fresh ginger extract in the form of increased yield (3.04-fold), TFC values (12.25-fold), reducing power (FRAP) (15.35-fold), total antioxidant activity (TAA) (6.82-fold) and inhibition of ABTS•+ radical cation (3.51-fold) and DPPH• radical (95%). Meanwhile, freeze-dried aqueous ginger extracts demonstrated significantly higher TPC (1.66-fold), TFC (3.71-fold), FRAP (3.26-fold), TAA (2.97-fold), ABTS•+ scavenging activity (1.48-fold) and DPPH• radical inhibition (77%), compared to fresh ginger extracts. In addition, it was found that ethanol was significantly superior to aqueous ethanol in phenolic content recovery, despite the lower yield. Furthermore, ethanol ginger extracts exhibited higher antioxidant activity than aqueous ethanol extracts. On the other hand, hot water was the least potent solvent for extraction. In summary, there was an excellent correlation between TPC, TFC and antioxidant activity. Sun-drying is the most desirable method for preserving and enhancing ginger quality due to its cost effectiveness and bioactive compound efficacy.

Sage extracts obtained with cold plasma improves beef quality

The aim of the study was to verify the effect of sage extracts obtained using cold plasma on the quality of ground beef. Patties with a different content of sage extracts (0.05% and 0.075%) obtained either by conventional extraction (S0.05, S.0.075) or with cold plasma assistance (SP0.05, SP0.075) were packed under a modified atmosphere (80%O2) and stored in cold conditions for 8 days. Sage extracts addition had no impact on pH, weight loss, colour, content of each myoglobin form, texture, aroma and overall acceptability of raw meat measured on the last storage day (P < 0.05). However, lipid oxidation was inhibited the most in meat with the highest share of sage extract obtained using cold plasma (P < 0.05). This group was also characterized by the highest amount of n-3 fatty acids at the end of storage (P < 0.05). Moreover, the addition of sage at 0.075% prevented hexanal formation in samples. Thus, cold plasma extracts may be introduced in the meat industry.

Edible Wild Vegetables Urtica dioica L. and Aegopodium podagraria L.-Antioxidants Affected by Processing

Urtica dioica L. and Aegopodium podagraria L., also known as stinging nettle and ground elder, are edible wild green vegetables rich in bioactive and antioxidant polyphenols, vitamins, and minerals. Antioxidant activity assays (TEAC-, DPPH-, and TPC-assay) in combination with HPLC measurements, to qualify and quantify their chemical compositions, were used. Firstly, the drying methods affected the antioxidant activity of further processing stages, and outcomes were dependent on the species. Secondly, cooking increased the antioxidant activity due to higher concentrations of bioactive compounds, and released bound compounds through the rupture of cell structures. Furthermore, fridge storage (3 days at 7 °C) resulted in the lowest antioxidant activity, compared to freezer storage (30 days at -20 °C). Added 5-caffeoylquinic acid (0.3 mM) led to an increased antioxidant activity, most noticeably in freeze-dried samples. Synergistic effects of 5-caffeoylquinic acid were primary found in freeze-dried samples, analyzed fresh or after storage in the fridge. Metal-chelates can lower the antioxidant activity in plant matrices. Edible wild green vegetables are rich in polyphenols and processing can even increase their concentrations to boost the potential health effects. In general, selected quantified phenolics are not solely responsible for the antioxidant activity; minerals, processing, and interactions in plant matrices also contribute decisively.

Influence of Nitrogen Fertilizer on the Antioxidative Potential of Basil Varieties (Ocimum basilicum L.)

Total phenolic content (TPC) in extracts of basil depended on the cultivar and type of fertilization used in cultivation. TPC was determined spectrophotometrically with the Folin−Ciocalteu reagent. The antioxidant activity of extracts was analyzed by scavenging of DPPH and ABTS radicals, on the basis of metal chelating ability (MetChel) and ferric reducing antioxidant power (FRAP). The greatest TPC was determined in the purple cultivars—141.35 and 165.44 mg gallic acid/g d.m. for fertilized with ammonium nitrate (NH4NO3) and ammonium sulfate ((NH4)2SO4), respectively. Their extracts had the greatest antioxidant capacity in the majority of the methods used. The results varied depending on the modelling system used. The amount of polyphenols in individual basil cultivars differed significantly (p < 0.05) depending on the fertilization used in the culture. Regarding TPC, DPPH, ABTS, FRAP, and MetChel variables, we observed a significant effect for the applied cultivation. In the case of MetChel factor, lower results of all investigated basil species were observed for cultivation with ammonium sulfate. PCA demonstrated in the present study shows that Sweet and Cinnamon Basil samples cultivated with ammonium nitrate create a separated group. We recommend cultivation with ammonium sulfate fertilizers for these varieties of basil. The high content of phenolic compounds demonstrated in Sweet and Cinnamon Basil cultivated with ammonium sulfate, and thus associated antioxidant activity, indicates that it can constitute a valuable source for bioactive compounds in a balanced diet.

Effect of High-Humidity Hot Air Impingement Steaming on Cistanche deserticola Slices: Drying Characteristics, Weight Loss, Microstructure, Color, and Active Components

Cistanche deserticola is one of the most precious herbal medicines and is widely used in the pharmaceutical and healthy food industries. Steaming is an important step prior to drying in the processing of C. deserticola. This research investigated the effects of high-humidity hot air impingement steaming (HHAIS) parameters such as temperature, time, and relative humidity (RH) on drying characteristics, weight loss, color, microstructure, and active components of C. deserticola slices. The results showed that the steaming process caused a weight loss in C. deserticola; however, increasing the RH reduced the weight loss. Starch gelatinization observed from the microstructure of the steamed samples explained their long drying time. The Page model can well fit the drying process with a high R² (>0.956) under the drying conditions of 60°C and 6 m/s. Steaming increased the content of phenylethanoid glycosides, and the highest content was obtained at 95°C and 60% RH for 20 min, 75°C and 70% RH for 20 min, and 75°C and 60% RH for 30 min. The steamed samples appeared in an oil black color. When the color difference (ΔE) values were in the range of 16.79–20.12, the contents of echinacoside and acteoside reached the maximum. Steaming at 95°C and 60% RH for 20 min, 75°C and 70% RH for 20 min, and 75°C and 60% RH for 30 min are the optimum process conditions. The results from this work provide innovative steaming technology and suitable processing parameters for producing C. deserticola decoction pieces with a high quality, which will broaden its potential application in the functional health food industry.

Total Polyphenols and Antioxidant Properties of Selected Fresh and Dried Herbs and Spices

In this study, the content of total polyphenols (TP) and the antioxidant activity (AA) of fresh herbs (13 in total) and those subjected to the freeze-drying process (stems and leaves separately) were compared. Moreover, the content of TP and AA of retail, commercial food spices (19 in total) of the two leading companies on the Polish market were compared. The novelty of our studies is the comparison between fresh and dried forms of herbs and spices and additionally between dried in a freeze-drying process and commercially available (in dried forms). It was found that fresh herbs and spices showed a large accumulation of polyphenolic compounds (from 466.55 to 17.23 CAE/100 g, respectively, for lemon balm and ginger). For freeze-dried herbs and spices, the highest TP content was found for marjoram (3052.34 CAE/100 g—leaves). Among commercial herbs and spices, sage (971.28 CAE/100 g) deserves attention. Fresh herbal spices, in particular oregano, (236.21 µM TE/g) had the highest AA. AA of freeze-dried herbs and spices was much lower (5.27–1.20 µM TE/g). The average value obtained for commercially available herbs and spices purchased was 1.44 µM TE/g. In the case of AA measured by the DPPH radical, thyme was characterized by the highest activity among fresh marjoram for freeze-dried herbs and spices. For dried commercial spices, the highest levels of AA were found for cumin.

Comparison between Quality Traits of Solar-Dried and Freeze-Dried Origanum syriacum L. (Za'atar)

There is growing interest in Origanum syriacum due to attractive culinary applications and functional properties. Solar drying is the most common conventional method for drying Origanum syriacum L. (Za’atar) in Mediterranean region. This study aimed to evaluate the quality traits of solar dried za’atar in comparison to freeze dried za’atar. Proximate composition (moisture, protein, fat, fiber, carbohydrates, and ash), color index (L*a*b*), macro and microstructure, sensory, and microbiological characteristics were evaluated. Solar dried za’atar exhibited significantly lower fat content (1.10 vs. 1.64%, p < 0.05) than freeze dried za’atar. Solar drying led to severe changes in color values compared to freeze drying. Solar drying exhibited loss in the structural integrity and leave hairs more than freeze drying. Moreover, freeze-dried za’atar exhibited significantly lower total aerobic count (4.92 vs. 5.23, p < 0.05) and yeasts and mold count (4.59 vs. 5.36, p < 0.05) than solar-dried za’atar. Panelists were able significantly to differentiate between solar- and freeze dried za’atar. Freeze-dried za’atar had significantly lower hedonic score of color, odor, taste, and overall acceptance than solar dried za’atar. In conclusion, using freeze drying achieved good improvements in some quality traits for za’atar while solar dried za’atar showed better sensory perception.

Anti-migraine activity of freeze-dried latex obtained from Calotropis gigantea Linn

Migraine which is characterized by a pulsating headache affected an estimated population of 12% worldwide. Herbal products like latex derived from Calotropis gigantea R. Br. (Asclepiadaceae) are a representative intervention to treat migraine traditionally. However, post-harvesting stability issues of latex affect its biological potential. Freeze-drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable dried preparations. Latex derived from Calotropis gigantea (C. gigantea) was microencapsulated using chitosan by freeze-drying (FDCG) method and compared with sun ray-dried latex (ADCG). Current investigation was aimed to improve the shelf life of latex by freeze-drying microencapsulation technique and evaluation of its anti-migraine potential. Dried latex powders (ADCG and FDCG) were evaluated in terms of phenolic content, coloring strength, first-order kinetic, color parameters (L*, a*, b*, C*, and E*), moisture, water activity, solubility, and hygroscopicity. Additionally, apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity were used to evaluate the anti-migraine potential of powdered latex. FDCG showed good physicochemical properties due to its higher concentration of phenolic and flavonoid contents. Moreover, FDCG significantly reduced the apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity in a dose-dependent manner through an interaction of dopaminergic and serotonergic receptors. In conclusion, the method developed for shelf life improvement of latex offered maximum protection over a period of 10 weeks with retaining its natural biological potential; thus, it can be effectively utilized in the treatment or management of migraine. Anti-migraine effect of Calotropis gigantea freeze-dried latex by inhibition of dopamine and serotonin receptors (D1 and D2: dopamine receptors; 5-HT: serotonin receptors); yellow color represents serotonergic, and blue color indicates dopaminergic neurons.

The antioxidant properties and microbial load of Moringa oleifera leaves dried using a prototype convective air-dryer

The recent COVID-19 pandemic resulted in major postharvest losses because most fresh produce could not be sold. Drying is an important thermal-based food preservation method which could have prolonged the shelf-life of these produce, but most drying technologies are costly, and cannot be afforded by small-time farmers. From this context, we were interested in evaluating the drying of Moringa oleifera leaves (MOL) using a low-cost self-built prototype convective-air dryer (CAD), alongside conventional drying methods for its antioxidant properties, microbial load and phytoconstituents. Results showed total polyphenol content was the highest (p < 0.05) in our CAD samples, and it retained among the highest total flavonoid content, total antioxidant capacity, total alkaloid content and DPPH radical scavenging activity. Furthermore, methanolic CAD extract presented lower coliform and yeast and mold count than the aqueous CAD extract. We also briefly explored MOL as a sanitizer where the microbial load of the methanolic extract was comparable (p > 0.05) with several commercial non-alcoholic sanitizers, indicating its commercialization potential as a bio-friendly sanitizer. Finally, using GC–MS, we are the first to report (best of our knowledge) on the presence of caprolactam, an important bio-medical field compound, in the CAD sample’s aqueous extract.

The Changes in Bioactive Compounds and Antioxidant Activity of Chia (Salvia hispanica L.) Herb under Storage and Different Drying Conditions: A Comparison with Other Species of Sage

Studies on herb chia (Salvia hispanica L.) are very limited. Therefore, the aim of this study was to assess how different drying methods and periods of storage affect the bioactive properties of the herb Salvia hispanica and to compare it with other species of sage (Salvia officinalis L. and Salvia sclarea L.). In fresh herbs, directly after drying (freeze-drying, natural drying, and drying at 30, 40, and 50 °C), and after storage (3, 6, and 12 months), the following analyses were performed: content of total carotenoids and total polyphenols, polyphenol profile (including 25 compounds), and antioxidant activity. Additionally, the basic chemical compositions of the herbs were analyzed. To the best of our knowledge, the content of total carotenoids and the quantitative polyphenol profile in Salvia hispanica and Salvia sclarea were evaluated for the first time. The obtained results showed that the barely investigated herb Salvia hispanica is rich in polyphenolic compounds and shows high antioxidant activity. In all the tested species, rosmarinic acid was the most abundant polyphenolic compound. The use of different drying methods allowed us to determine that freeze-drying was the most effective for preserving polyphenols and carotenoids. Long-term storage up to 12 months resulted in a gradual reduction in antioxidant activity and in the content of polyphenols and carotenoids.

Effects of Different Pre-drying and Drying Methods on Volatile Compounds in the Pericarp and Kernel of Amomum tsao-ko

The effects of twelve different pre-drying and drying methods on the chemical composition in the pericarp and kernel of Amomum tsao-ko were studied. The volatile components were isolated from the samples by simultaneous distillation and extraction and analyzed by gas chromatography-mass spectrometry (GC-MS). Sixty and thirty-eight compounds were identified from pericarp and kernel, respectively, and the main constituents were oxygenated monoterpenes. These compounds were not only significantly affected by pre-drying and drying methods but also varied in content due to different tissue locations. The total volatile content of pericarp varied from 0.70 to 1.55%, with the highest obtained by microwave-dried samples (150 W) and the lowest in freeze-dried samples. The total volatile content of the kernel varied from 6.11 to 10.69%, with the highest content obtained during sun drying (SD) and the lowest content in samples treated with boiling water for 2 min. Oxygenated monoterpenes were the highest compounds in pericarp and kernel, which were also the most affected by drying methods. The highest content of oxygenated monoterpenes in the pericarp (0.77%) could be obtained by boiling water treatment for 5 min, and the highest content of oxygenated monoterpenes in the kernel (7.48%) could be obtained by SD. Additionally, the main components such as 1,8-cineole, 2-carene, (Z)-citral, nerolidol, (Z)-2-decenal, (E)-2-dodecenal, citral, (E)-2-octenal, 4-propylbenzaldehyde, and phthalan showed remarkable variations in pre-drying and drying methods.

Essential Oils Extracted from Organic Propolis Residues: An Exploratory Analysis of Their Antibacterial and Antioxidant Properties and Volatile Profile

The industrial processing of crude propolis generates residues. Essential oils (EOs) from propolis residues could be a potential source of natural bioactive compounds to replace antibiotics and synthetic antioxidants in pig production. In this study, we determined the antibacterial/antioxidant activity of EOs from crude organic propolis (EOP) and from propolis residues, moist residue (EOMR), and dried residue (EODR), and further elucidated their chemical composition. The EOs were extracted by hydrodistillation, and their volatile profile was tentatively identified by GC-MS. All EOs had an antibacterial effect on Escherichia coli and Lactobacillus plantarum as they caused disturbances on the growth kinetics of both bacteria. However, EODR had more selective antibacterial activity, as it caused a higher reduction in the maximal culture density (D) of E. coli (86.7%) than L. plantarum (46.9%). EODR exhibited mild antioxidant activity, whereas EOMR showed the highest antioxidant activity (ABTS = 0.90 μmol TE/mg, FRAP = 463.97 μmol Fe²⁺/mg) and phenolic content (58.41 mg GAE/g). Each EO had a different chemical composition, but α-pinene and β-pinene were the major compounds detected in the samples. Interestingly, specific minor compounds were detected in a higher relative amount in EOMR and EODR as compared to EOP. Therefore, these minor compounds are most likely responsible for the biological properties of EODR and EOMR. Collectively, our findings suggest that the EOs from propolis residues could be resourcefully used as natural antibacterial/antioxidant additives in pig production.

Biochemical parameters and antioxidant property of three Salvia L. taxa endemic in Turkey

The aim of the present study was to determine and compare the fatty acids, lipid soluble vitamins, sterols, phenolics, and antioxidant capacities of three endemic Salvia L. taxa (S. euphratica var. Montbret & Aucher ex Bentham leiocalycina (Rech. Fil.) Hedge, S. euphratica var. Montbret & Aucher ex Bentham euphratica (Rech. Fil.) Hedge and S. pseudoeuphratica Rech.Fil.) and to evaluate these results systematically. The fatty acid compositions were determined by using gas chromatography, while the lipid soluble vitamins, sterols, and phenolics were determined by using HPLC. Also, the antioxidant capacities of three Salvia taxa were measured in vitro. Palmitic acid was found as major saturated fatty acid while oleic acid, linoleic acid, α-linolenic acid, and erucic acid were found as major unsaturated fatty acids in the present study. It was found that S. euphratica var. euphratica had lower palmitic acid (8.94 ± 0.71%), total saturated fatty acid (19.16 ± 0.15%), and higher unsaturated fatty acid content (82.08 ± 0.52%) than other studied taxa. Furthermore, it was shown that S. euphratica var. euphratica had different 18.3/18:2 (0.36) unsaturated/saturated fatty acid (4.28) ratios. However, this study demonstrated that Salvia taxa had low lipid soluble vitamins, sterol contents. On the other hand, it was shown that Salvia taxa had similar catechin (509.2 ± 4.21 µg/g and 552.2 ± 9.21 µg/g) and vanillic acid amounts (351.2 ± 2.17 µg/g and 396.8 ± 4.1 µg/g) in this study. And also, it was found that Salvia taxa had high rosmarinic acid content while S. euphratica var. leiocalycina had the highest rosmarinic acid content (1480 ± 7.57 µg/g). On the other hand, it was shown that the two ferulic acid contents of S. euphratica varieties were higher (1175 ±/5.21 µgmg-1740.2 ± 4.82 µg/mg) than the ferulic acid content of S. pseudoeuphratica of which was the lowest (19.2 ± 0.97 µg/mg). The present results suggested that the biochemical results guided the morphological studies, and Salvia taxa have a potent antioxidant capacity.

Effect of different drying methods on product quality, bioactive and toxic components of Ginkgo biloba L. seed

BACKGROUND

Ginkgo biloba seeds are used as a functional food across Asia. However, the presence of toxic compounds has limited their application. In this study, freeze drying, infrared drying, hot-air drying and pulsed-vacuum drying were used to dry G. biloba seeds. A comprehensive analysis was performed on their product quality, antioxidant activities, bioactive and toxic components.

RESULTS

Results showed that the drying methods had a significant influence on product quality with freeze drying being superior due to the minimal microstructural damage, followed by infrared drying and pulsed-vacuum drying. Infrared-dried product possessed the strongest antioxidant activities and higher bioactive compound content than hot-air-dried and pulsed-vacuum-dried product. Toxic compounds in fresh G. biloba seeds (ginkgotoxin, ginkgolic acid and cyanide) were reduced markedly by drying. Ginkgotoxin was reduced fourfold, and the contents of acrylamide, ginkgolic acid and cyanide in dried G. biloba seeds were reduced to the scope of safety. Amongst the four drying methods, infrared drying had the shortest drying time, and its product showed higher quality and bioactive compound content, and stronger antioxidant activities.

CONCLUSIONS

These findings will offer salient information for selecting a drying method during the processing of ginkgo seeds. Infrared drying could be considered as a multiple-effect drying method in the processing of ginkgo seeds. © 2020 Society of Chemical Industry.

Effect of different drying processes on an antioxidant potential of three species of the Lamiaceae family

Introduction: Spice plants are a rich source of biologically active compounds. Processes of drying, limits the development of microorganisms and biochemical reactions in raw herbs, at the same time modifies their chemical composition.

Objective: The aim of this work was to evaluate the effect of drying process of selected plants on their anti-oxidant potential and the content of biologically active compounds.

Methods: The herbal materials thyme herb (Thymus vulgaris L.), sage leaves (Salvia officinalis L.) and rosemary leaves (Rosmarinus officinalis) were dried using two methods: convective (at 30° C), and freeze-drying. In both, fresh and subjected to drying processes herbs, changes in total polyphenol and antioxidant potential (with the DPPH radical), vitamin C (in the form of ascorbic acid) and chlorophyll pigments contents, were studied.

Results: The highest content of polyphenols and vitamin C was recorded in rosemary, while sage was characte- rized by the highest content of chlorophylls. It was found that the drying processes caused large losses of vitamin C (ascorbic acid) and dyes in comparison to the fresh material. The highest losses of vitamin C occurred in convection dried sage (95%), while most was preserved in lyophilised thyme (losses 74%). Drying had also influenced the reduction of the content of chlorophylls with the largest loss of these compounds, at 94% observed in the freeze-dried rosemary. However, the content of polyphenols increased, underscoring a large impact on the antioxidant activity of herbs.

Conclusions: Drying processes resulted in the release of phenolic compounds, so their content increased three to four times in the case of rosemary and sage. The largest increase was observed in the case of lyophilised thyme. Simultaneously, the antioxidant potential was significantly increased. Herbal droughts proved to be a rich source of antioxidant compounds with promising applications as a food additive.

Origanum syriacum L. (Za'atar), from Raw to Go: A Review

The interest in za'atar has increased in recent years due to its economic, cultural, and functional importance. The traditional za'atar mix made from dried Origanum syriacum is now a demanded product nationally and internationally. Air-drying at low temperatures can preserve za'atar quality traits better than other techniques such as oven-drying. The Palestinian za'atar market has the potential to develop and increase its value. However, it is facing many challenges. Another valuable product of za'atar is essential oil. Za'atar essential oil quantity and quality are affected by many factors including geographical location, cultivation, harvesting season, soil, extraction method, temperature, and others. These factors interact with za'atar and with each other; therefore, some factors are more effective than others and further research is needed to determine the optimum condition for producing and obtaining za'atar essential oil. Antimicrobial and antioxidant activities are the main functionalities of za'atar essential oil that are behind its medicinal importance. One hundred and twenty-one compounds have been identified in za'atar essential oil. The most common compounds are thymol, γ-terpinene, carvacrol, and α-pinene. The variation in the composition among za'atar essential oil samples results from the different conditions of the studies during za'atar growth as well as essential oil extraction.

Six Common Herbs with Distinctive Bioactive, Antioxidant Components. A Review of Their Separation Techniques

Rosemary, oregano, pink savory, lemon balm, St. John’s wort, and saffron are common herbs wildly grown and easily cultivated in many countries. All of them are rich in antioxidant compounds that exhibit several biological and health activities. They are commercialized as spices, traditional medicines, or raw materials for the production of essential oils. The whole herbs or the residues of their current use are potential sources for the recovery of natural antioxidant extracts. Finding effective and feasible extraction and purification methods is a major challenge for the industrial production of natural antioxidant extracts. In this respect, the present paper is an extensive literature review of the solvents and extraction methods that have been tested on these herbs. Green solvents and novel extraction methods that can be easily scaled up for industrial application are critically discussed.

Effects of Drying Methods on Antioxidant, Anti-Inflammatory, and Anticancer Potentials of Phenolic Acids in Lovage Elicited by Jasmonic Acid and Yeast Extract

The study presents the effect of drying methods (traditional, convection, microwave, and freeze-drying) on the content and bioactivity (determined as antioxidative, anti-inflammatory, and antiproliferative potential) of potentially bioavailable fractions of phenolic acids contained in lovage elicited with jasmonic acid (JA) and yeast extract (YE) and in untreated control leaves. The highest amount of syringic acid was recorded in the convectionally dried lovage samples, while ethanolic extracts from lyophilized lovage had the highest content of protocatechuic and caffeic acids. The drying method significantly influenced the tested properties only in some cases. The traditional drying resulted in lower antioxidant potential, while convectional drying caused a reduction of the lipoxygenase inhibition ability of the samples after simulated digestion. Samples containing the control and elicited lovage leaves dried with convectional and traditional methods exhibited the highest cytotoxicity against a prostate cancer epithelial cell line.

Harvest time affects antioxidant capacity, total polyphenol and flavonoid content of Polish St John's wort's (Hypericum perforatum L.) flowers

The polyphenol content and antioxidant capacity of hyperforin and hypericin-standardized H. perforatum L. extracts may vary due to the harvest time. In this work, ethanol and ethanol-water extracts of air-dried and lyophilized flowers of H. perforatum L., collected throughout a vegetation season in central Poland, were studied. Air-dried flowers extracts had higher polyphenol (371 mg GAE/g) and flavonoid (160 mg CAE/g) content, DPPH radical scavenging (1672 mg DPPH/g), ORAC (5214 µmol TE/g) and FRAP (2.54 mmol Fe2+/g) than lyophilized flowers extracts (238 mg GAE/g, 107 mg CAE/g, 1287 mg DPPH/g, 3313 µmol TE/g and 0.31 mmol Fe2+/g, respectively). Principal component analysis showed that the collection date influenced the flavonoid and polyphenol contents and FRAP of ethanol extracts, and DPPH and ORAC values of ethanol-water extracts. The ethanol extracts with the highest polyphenol and flavonoid content protected human erythrocytes against bisphenol A-induced damage. Both high field and benchtop NMR spectra of selected extracts, revealed differences in composition caused by extraction solvent and raw material collection date. Moreover, we have shown that benchtop NMR can be used to detect the compositional variation of extracts if the assignment of signals is done previously.

Effect of steam blanching and high temperature drying on the physicochemical properties, antioxidant activities and consumer acceptability of Hibiscus cannabinus leaves tea

Kenaf (Hibiscus cannabinus) leaves are produced as the by product when kenaf stems were harvested. The kenaf leaves was examed for the applicable possibility as herbal tea due to their rich phenolic content. In this study, the effect of steam blanching and high temperature drying on physicochemical properties, antioxidant activity and consumer acceptability of the kenaf tea leaves were studied. Results showed that steam blanching prior oven-drying improved the extractability of phenolic compounds, leading to the increase in total flavonoid content, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and ferric reducing antioxidant power. Drying at 120 °C was able to preserve more phenolic compounds, at the same time developing better taste, mouthfeel, and overall acceptability of kenaf leaves tea. Caffeic acid, tannic acid, catechin, and chlorogenic acid in kenaf tea leaves infusion were analyzed by ultra high performances liquid chromatography. In conclusion, steam blanching prior to 120 °C oven-drying was the best process method for the production of kenaf leaves into acceptable tea type.

KONDISI OPTIMUM PERLAKUAN AWAL DAN PENGERINGAN KULIT BUAH NAGA KERING

Antioxidant plays an important role in keeping the body health. Antioxidant is needed to prevent the occurrence of oxidative stress, which causes of various degenerative diseases. Betacyanin in the dragon fruit peel takes part in antioxidant activity. The research is conducted using the central composite design (CCD) of the response surface methodology (RSM). This research aims to optimize the initial treatment condition by applying natrium metabisulfite immersion and drying on the dried dragon fruit peel. Three design composite factors used are natrium metabisulfite concentration (X1: 0.2-0.4%), drying temperature (X2: 65-75°C), and drying duration (X3: 4-5 hours) with betacyanin content (Y1) and antioxidant activity (Y2) as the response. A quadratic model is a method chosen for this research. The surface response showed the natrium metabisulfite concentration, temperature, and drying duration had signifi-cant effects on the betacyanin content and antioxidant activity. The most optimum condition of initial treatment is showed by immersion in 0.23% natrium metabisulfite and drying temperature of 70°C for 4.5 hours which resulted in 44.07 mg/100 g of betacyanin concentration and 50.56% antioxidant activity.

Bioactive activities and chemical profile characterization using paper spray mass spectrometry of extracts of Eriobotrya japonica Lindl. leaves

RATIONALE

The loquat (Eriobotrya japonica Lindl.) is a fruit tree that has been used in Chinese medicine for thousands of years for the treatment of various diseases. The loquat leaf extracts contain several bioactive compounds with antioxidant and antimicrobial properties, and identification of these substances using quick and simple methods has been an analytical trend.

METHODS

The influence of dehydration of loquat leaves (without drying, at 40°C, and at 60°C), the type of solvent (ethanol and methanol), and the method of extraction (shaking and ultrasound) on obtaining extracts containing phenolic compounds and substances with antioxidant and antimicrobial properties was evaluated. The chemical constituents of an extract were identified using paper spray mass spectrometry (PS-MS).

RESULTS

The extract obtained from the dehydrated leaves at 40°C presented the best results. The extracts obtained from these leaves and with ethanol had the highest values of total phenolics and antioxidant activities, but the methanolic extract subjected to ultrasound had the highest levels of chlorogenic, caffeic, and ellagic acids. All extracts evaluated inhibited the growth of Staphylococcus aureus. Using the PS-MS technique, it was possible to identify the presence of 49 substances such as organic acids, phenolic acids, flavonoids, sugars, quinones, and terpenes.

CONCLUSIONS

In general, extracts of dehydrated leaves at 40°C and extracted with ethanol using ultrasound can be considered a good source of bioactive compounds with potential applications as functional ingredients or additives in the food and pharmaceutical industries. PS-MS was demonstrated to be a simple and ultrafast technique to obtain the chemical profile of the loquat leaf extract.

Evaluation of Structurally Different Ionic Liquid-Based Surfactants in a Green Microwave-Assisted Extraction for the Flavonoids Profile Determination of Mangifera sp. and Passiflora sp. Leaves from Canary Islands

Aqueous solutions of ionic liquids (ILs) with surface active properties were used as extraction solvents, taking advantage of their impressive solvation properties, in a green microwave-assisted solid-liquid extraction method (IL-MA-SLE) for the extraction of flavonoids from passion fruit and mango leaves. The extraction method was combined with high-performance liquid chromatography and photodiode-array detection (HPLC-PDA) and optimized by response surface methodology using the Box-Behnken experimental design. Under optimum conditions, the extraction efficiency of six structurally different IL-based surfactants was evaluated. Thus, imidazolium-, guanidinium- and pyridinium-type ILs with different tailorable characteristics, such as side chain length and multicationic core, were assessed. The decylguanidinium chloride ([C10Gu+][Cl-]) IL-based surfactant was selected as key material given its superior performance and its low cytotoxicity, for the determination of flavonoids of several samples of Passiflora sp. and Mangifera sp. leaves from the Canary Islands, and using as target analytes: rutin, quercetin and apigenin. The analysis of 50 mg of plant material only required 525 µL of the low cytotoxic IL-based surfactant solution at 930 mM, 10.5 min of microwave irradiation at 30 °C and 50 W, which involves a simpler, faster, more efficient and greener method in comparison with other strategies reported in the literature for obtaining bioactive compounds profiles from plants.

Optimization of the antioxidant capacity of mangosteen peels (Garcinia mangostana L.) extracts: Management of the drying extraction processes

Mangosteen peel is a source of natural phenolic antioxidants. During processing, the quality and quantity of these compounds in the final product are altered. Sometimes, the important causal relationships are not easy to establish and thus process management is difficult. This is especially true when biochemical changes can occur as in the case of the drying and extraction process of bioactive materials. The aim of this work was to formulate and solve an optimization problem in order to obtain the appropriate values of the operating conditions that maximize the antioxidant capacity of the dried mangosteen peel extracts. The drying process was analyzed under different drying air temperatures (T) (50℃, 60℃, 70℃ and 80℃) at air velocity of 1 ms^-1. The extraction process was done under conventional and ultrasound-assisted extraction at 400 W. Antioxidant capacity was measured by 1,1-diphenyl-2-picrylhydrazyl assay. To solve the optimization problem formulated, an artificial neural network was developed. The resolution of the optimization problem allowed the establishment of the optimal operating conditions of the process, maximizing the antioxidant capacity values depending on the characteristics of the process. Results showed that the best operating conditions to maximize the antioxidant capacity of mangosteen peels were a drying temperature of 70℃ and using high-power ultrasound as extraction method.

Influence of Drying Temperature on the Content of Bioactive Compounds in Scots Pine (Pinus sylvestris L.) Shoots as Well as Yield and Composition of Essential Oils

The study concerns the effects of drying process conditions (40, 50, 60°C) on the contents of bioactive compounds in Scots pine (Pinus sylvestris L.) shoots as well as the yield and composition of essential oils. The obtained dry material was examined for the total contents of polyphenols and the antioxidant activity as well as the content of vitamin C. The material was examined by using the HS-SPME method, and the composition of the essential oils was determined using gas chromatography method (GC-MS). The highest contents of bioactive compounds were found in the material subjected to drying at 40°C. The highest yield of essential oils (0.63 ml 100 g−1 d.m. of the material) was obtained from the pine shoots dried at 40°C.

Drying Induced Impact on Composition and Oil Quality of Rosemary Herb, Rosmarinus Officinalis Linn

The natural drying of Rosmarinus officinalis Linn. herbs severely affects its volatile oil quality and yields, which is reported here for the first time. The oils obtained through hydrodistillation from fresh, one, two, and three-weeks dried herbs were analyzed by gas chromatography–mass spectroscopy (GC–MS) and gas chromatography–flame ionization detector (GC-FID), and the yields were 198 ± 3.45, 168.7 ± 5.11, and 97.8 ± 1.27 mg, respectively, as compared to the internal referral standard of 327 ± 5.91 mg yield of the one-week dried herbs’ oil. Camphor, the major constituent, significantly depleted from 20.96% to 13.84%, while bornyl acetate yields increased from 1.42% to 12.46% (p values < 0.0001) in three-weeks drying, reflecting the redox processes undergoing within the oil during drying. Several constituents (25) were found in one-week dried herbs’ oil as compared to the fresh, two-, and three-weeks oils, which consisted of 23, 19, and 14 constituents, respectively, leading to the recommendation of the one-week drying of the herb for maximum oil yield. The DPPH (2, 2-diphenyl-1-picryl-hydrazyl) reactivity was highest for the two- and three-weeks dried herb-based oils, followed by the one-week dried- and fresh-herb-based oils (p < 0.0001), again indicating major chemical changes during herbs’ dryings, affecting the free-radical scavenging capacity of these batches of oils obtained after different drying times.