Electronic nose to differentiate between several drying techniques for Origanum syriacum leaves

Dried oregano (Origanum syriacum L.) is a common product in the Mediterranean diet and it has wide culinary applications. The quality and functional ingredients profile of oregano is highly affected by drying technology. This study was aimed to discriminate different quality traits of air, solar, and freeze-dried oregano by employing electronic nose (e-nose), chromameter, and sensory analysis. E-nose signals were analysed by using multivariate data analysis (MVDA). Our findings showed that the e-nose signal exhibited different clusters for all groups by using principal component analysis (PCA). Moreover, there were clear differences in the colour index (L*a*b*) between groups. Freeze-dried oregano exhibited significantly lower L*-values than air and solar-dried oregano. Sensory analysis showed that there were clear differences between solar and freeze-dried oregano. In this context, f-dried thyme had significantly lower values of colour acceptance (4.80 vs. 7.57, p<0.05), degree of freshness (5.57 vs. 7.14, p<0.05), taste acceptance (5.46 vs. 6.75, p<0.05), and overall acceptance (5.75 vs. 7.19, p<0.05) than solar-dried thyme, respectively. In conclusion, e-nose and chromameter were effective tools to discriminate between different types of dried oregano

POLYPHENOLS IN OLIVE LEAVES AND THEIR ANTIOXIDANT ROLE -A BRIEF REVIEW

Exercise and sports can often be associated with oxidative stress, which is why modulation of oxidative stress in these situations is important. One of the natural remedies that has proven to be very useful antioxidant, due to its composition, is the oliveleaf extract.Olive leaves. The leaves are considered a by-product of the olive. Freezing techniques as well as leaf drying techniques influence the composition in polyphenols. The leaves have a high content of bioactive phenolic compounds. The most abundant compound in olive leaves is oleuropein, followed by hydroxytyrosol. Olive leaves have been used in the human diet in the form of extracts, tea and powder but also in the realization of traditional remedies in the Mediterranean countries. The compounds in olive leaves have been shown to have multiple beneficial properties, such as antioxidants. compared to olive oil.Instead of conclusions.Due to their rich polyphenolic composition, olive leaves have strong antioxidant effects, proven by traditional use and scientific studies.

Applicability of Spray Drying Technique to Prepare Nano-Micro Carriers: A Review

Nano-micro carriers loaded with drugs and active biomolecules have gained a lot of attention in the field of health care, agriculture, and the food industry. Various methods have been explored to synthesize nano-micro carriers. However, there is still a constant search to develop a method for the preparation of a large quantity of nano-micro carriers with high loading efficiency. In this regard, spray drying could be a potential technique because of its inherent features like ease to operate, cost-effectiveness, environment-friendly, single step, and scalable. In this review, the focus is on the applicability of spray drying technique to prepare nano-micro carriers which are loaded with drugs, microorganisms, and other active molecules. Subsequently, the application and usefulness of spray-dried products in different research areas like the food industry, remediation of heavy metals and bioprocessing, and drug delivery have been presented. Furthermore, advantages, limitations, and recent developments in the area of spray drying have been discussed. This review presents a glimpse of spray drying techniques to synthesize nano-micro carriers with a wide range of applications.

Evaluation of Freeze Drying and Electrospinning Techniques for Saffron Encapsulation and Storage Stability of Encapsulated Bioactives

Saffron extract was encapsulated into a gelatin matrix by means of electrospinning and freeze drying techniques and the degradation kinetics of bioactive compounds were evaluated during their storage at 4, 24, and 35 °C as compared to non-encapsulated control. The encapsulation efficiency, thermal properties, storage stability, morphology, and diameter distribution of the encapsulated saffron extract were evaluated as output parameters. In general, both encapsulation techniques demonstrated superior retention of bioactive compounds compared to samples without encapsulation during the entire storage period. Electrospinning and freeze drying techniques were able to retain at least 96.2 and 93.7% of crocin, respectively, after 42 days of storage at 35 °C with the 15% saffron extract. The half-life (t1/2) time parameter for the control sample (with 15% saffron extract without encapsulation) was 22 days at 4 °C temperature, while that encapsulated by electrospinning was 138 days and that obtained for freeze drying was 77 days, The half-lives were longer at lower temperatures. The encapsulation efficiency of crocin, picrocrocin, and safranal associated with the electro-spun gelatin fibers were 76.3, 86.0, and 74.2%, respectively, and in comparison, the freeze drying encapsulation efficiencies were relatively lower, at 69.0, 74.7, and 65.8%, respectively. Electro-spun gelatin fibers also had higher melting and denaturation temperatures of 78.3 °C and 108.1 °C, respectively, as compared to 65.4 °C and 93.2 °C, respectively, for freeze-dried samples. Thus, from all respects, it was concluded that electrospinning was a better and more effective technique than freeze drying in terms of preserving saffron bioactive compounds.

COMPARISON OF TWO MICROWAVE DRYING TECHNIQUES FOR CEREAL SEEDS AND DETERMINATION OF THEIR PHYSICAL PARAMETERS

The microwave drying of wheat and corn seeds by two technologies at different working powers is studied here. The main objective is to evaluate the effect of microwaves on variations in the moisture, colour and size of the seeds after microwave drying. The tests are performed in microwave ovens with and without inverter technology at three drying powers (260, 440 and 620 W). It has been observed that increasing drying power results in a ~50% reduction in drying time and a seed moisture level below 14%. The colour variation of the seeds is insignificant between microwave drying with and without the inverter. However, there is also an unacceptable decrease in size for both types of seeds with increasing drying power, which can lead to increased shrinkage of the seeds and the appearance of cracks, especially in the corn seeds.

Influence of Drying Techniques on the Physicochemical, Nutritional, and Morphological Properties of Bighead Carp (Hypophthalmichthys nobilis) Fillets

Different experiment analyses were performed to evaluate the influence of two drying techniques (oven drying and microwave drying) on the fillets of bighead carp fish (Hypophthalmichthys nobilis). The processed and fresh samples were subjected to the chemical analysis of (amino acids, minerals, volatile compounds, fatty acids, and vitamins) as well as scanning electron microscopy, thermal analysis, and color measurement, in order to identify nutritional components that can be additives or supplementary in food industries. The drying techniques increased the protein content significantly. Amino acids were identified, and the level of essential amino acid (EAA) was higher under the microwave treatment compared with the oven drying process. The Ca+2 and K+1 were presented in high values, followed by Na+1 and Mg+2. In addition, the drying techniques showed and released more volatile compounds in the processed samples compared with the unprocessed samples. Under the drying process, polyunsaturated fatty acids were increased in the processed fillets, whereas the level of saturated and monounsaturated fatty acids reduced. Thermal degradation occurred from 100 to 150 °C. However, the processed samples were subjected to an intensive endothermic response, but remained stable until 100 °C. Therefore, the microwave technique showed some enhancements in the nutritional value and has the potential to be applied as an effective preservation method of bighead carp fish. Furthermore, dried fillets could be an alternative source of bighead carp fish for the food industry.

Impact of Encapsulation Wall Materials and Drying Method on Physicochemical Properties and Digestibility of Encapsulated Chayote (Sechium edule (Jacq.) Swartz) and Kohlrabi (Brassica oleracea var gongylodes L.) Extracts

Chayote (Sechium edule (Jacq.) Swartz) and kohlrabi (Brassica oleracea var gongylodes L.) are medicinal plants widely distributed in Thailand. Several traditional medicines usually contain these extracts due to their pharmaceutical activities. However, appropriate technologies that are used for protection, stabilization, and slow release of plant extracts are a lot desired in terms of food application. In this study, chayote and kohlrabi extracts were encapsulated by several kinds of wall materials (maltodextrin, and the combination of maltodextrin and gum arabic or alginate) and drying methods (freeze-drying and tray-drying techniques). Thus, the objective of this research was to determine morphological and physicochemical properties, wall materials releasing, and antioxidant activity of encapsulated chayote and kohlrabi extracts powder. The morphology of all encapsulated chayote and kohlrabi extracts powder showed irregular spherical shape, monodispersity, and smooth surface. The encapsulated chayote and kohlrabi extracts powder with tray-drying technique tend to have more darkness and redness in color than the freeze-drying technique. Wall material releasing was expressed in glucose liberation of encapsulated extracts powder after amylolytic enzyme digestion. Encapsulation using maltodextrin as wall material provided higher wall material releasing than the other samples. After digestion analysis, the digested residues were examined for antioxidant activity. The results showed that the combination of maltodextrin and alginate for both freeze-drying and tray-drying techniques provided higher antioxidant activity after 60 and 120 min of digestion. Thus, the combination of maltodextrin and alginate, and drying with the freeze-drying technique was the best treatment in this experiment. This data can lead to a better understanding of wall materials types and releasing characteristics, which are used to control bioactive compounds liberation in the gastrointestinal tract.