An idea for a new modeling approach of climatic changes. A correlation study for Cyprus

Mathematical Modeling in climatic changes prediction has been based on more or less simple energy balances considering the Earth along with its atmosphere, with the so-called solar "constant" taken as an invariant. However evidence has been supplied in previous WSEAS Conferences that this constant, S, does not remain a constant but it does fluctuate, following the cycles of the solar activity. Furthermore the transmission parameters concerning the input and the output energy, τ V and τ IR from/to the system Earth-Atmosphere also vary and this reflects the human activity leading to increased greenhouse gas quantities, being blamed for a dramatic climatic change the last decades. Thus, considering those fluctuating properties, the following equation for Earth's mean temperature, T, has been developed (A being albedo equal to 0.3 and σ is the Stefan-Boltzmann constant) (Equation presented) with the following multivariate treatment: (Equation presented) We need to obtain the derivatives: (Equation presented) because all S, τ IR, τ V chang

Antioksidacijski i antimikrobni učinak ekstrakata tršlje (Pistacia lentiscus L.) u kobasicama od svinjskog mesa

Pistacia lentiscus fruits are ingredients of traditional Cypriot sausages. The objective of this study is to evaluate P. lentiscus extracts as natural additives to the sausages. First, the phenolic content and antioxidant activity of fruit and leaf extracts were determined. Results revealed that leaves are richer source of polyphenolic antioxidants than fruits, with methanol being the better extraction solvent. In the next step, the antioxidant and antimicrobial effects of methanolic extracts (300 mg/kg) in the pork sausage formulation were investigated. Peroxide, acid and thiobarbituric acid-reactive substance values demonstrated that both fruit and leaf extracts reduced the rate of lipid oxidation of sausages at 4 °C. Total viable count revealed significant differences on the fifth day of storage, with better microbial inhibition by leaf extract. No significant differences between the extracts were observed after the tenth day of storage. Overall, the extracts can be used to prevent lipid oxidation and reduce microbial spoilage during the first days of storage of fresh traditional pork sausages.Plod tršlje (Pistacia lentiscus) koristi se kao dodatak tradicionalno proizvedenim ciparskim kobasicama. Svrha je ovoga rada bila ispitati djelovanje ekstrakata tršlje kao prirodnih dodataka kobasicama. Prvo je određen udjel fenola u ekstraktima ploda i lista te je izmjerena njihova antioksidacijska aktivnost. Rezultati pokazuju da je lišće tršlje bogatije polifenolnim antioksidansima od plodova, a za njihovu je ekstrakciju najbolje upotrijebiti metanol. Zatim je ispitan antioksidacijski i antimikrobni učinak metanolnih ekstrakata (300 mg/kg) u kobasicama od svinjskog mesa. Peroksidni i kiselinski brojevi te koncentracija reaktivnih spojeva tiobarbiturne kiseline potvrđuju da se dodatkom oba ekstrakta smanjila oksidacija lipida u kobasicama na temperaturi skladištenja od 4 °C. Nakon pet dana skladištenja je u uzorcima kobasica s ekstraktima tršlje u usporedbi s kontrolnim uzorkom znatno smanjen ukupni broj živih stanica mikroorganizama, pri čemu je ekstrakt lišća imao bolji inhibicijski učinak. Nakon deset dana skladištenja nisu uočene bitne razlike u inhibicijskom učinku između ekstrakta ploda i lišća. Iz dobivenih rezultata moguće je zaključiti da se ekstrakti ploda i lišća tršlje mogu primijeniti za sprečavanje oksidacije lipida i produljenje trajnosti tradicionalnih kobasica od svježeg svinjskog mesa

Effect of drying method on the phenolic content and antioxidant capacity of spearmint

The changes in total phenolics, hydroxycinammic acid derivatives, and antioxidant properties of spearmint after five drying treatments (convection oven drying, freeze-drying, microwave drying, and air drying with the sun exposure and without the sun exposure) were investigated. Phenolic composition of dried spearmint was analysed by spectrophotometric assays, while DPPH radical scavenging activity and Ferric reducing/Antioxidant power (FRAP) assay was used to measure the antioxidant properties. The results showed that freeze drying produced dried spearmint that had the highest total phenolics (34.6 ± 1.9 mg/g) content and the most potent antioxidant capacity (126.2 ± 0.4 mg/g for FRAP and 88.1 ± 5.9 mg/g for DPPH, respectively). On the other hand, spearmint that was dried by convection oven and microwave drying presented the lowest amount of phenolic compounds (12.0 ± 0.5 mg/g) and antioxidant potency (49.3 ±0.7 mg/g for FRAP and 26.9± 1.6 mg/g for DPPH, respectively). This might be attributed to the fact that heat-sensitive phenolics were degraded or biotransformed at high temperatures. The loss of phenolic compounds and antioxidant activity reached up to 60% compared to freeze drying

Introducing the concept of sono-chemical potential: A phenomenological model for ultrasound assisted extraction

The current study presents a mathematical formulation that describes the role of ultrasonic irradiation in ultrasonic assisted extraction with thermodynamic terms. This model described the influence of ultrasound irradiation on the chemical potential of extracted compounds and predicted the increase of the yield of extraction using ultrasound irradiation. The term sono-chemical potential was described for the first time in an analogy to the piezo- or the electrochemical potential. Subsequently, the derived formula was applied on the extraction of polyphenols from spearmint, where the model showed the increase factor in the extracted amounts during ultrasound assisted extraction; the predicted value for a five minute extraction was 2.89 and the experimental values were 2.99, 2.92 and 2.32 for the hydroxycinnamic acid derivatives content, the antioxidant activity and the total phenolics respectively. The model could be further verified and used to explain the enhanced recovery of various compounds from diverse matrixes

Drying Technologies: Vehicle to High-Quality Herbs

Herbs are usually marketed as dry due to a consumer demand beyond their seasonality; dehydration leads to a stable, easily moveable product that is available throughout the year. The process of drying, though, leads to modifications in the appearance, composition and quality of the raw material. The extent of these alterations depends on the applied drying methodology and its parameters, rendering the optimization of this process imperative. Numerous studies examining the effect of drying on the main characteristics of herbs have been published in recent years, and this review aims at organizing the available information of the studied herbs, drying methods and measured parameters in a comprehensive manner. Primarily, since aroma is the main characteristic of herbs and the principal aim for the end product is to retain the raw material’s character, this review will focus on the most widely studied effect of drying, which is the essential oil yield and composition. Secondly, results from various studies on the influence of drying on biochemical compounds, organoleptic properties of dried herbs are also presented. The most common approach to the study of drying kinetics is also presented. Finally, novel technologies targeting to minimize the magnitude of changes from the raw material are described

Effect of drying method on the phenolic content and antioxidant capacity of spearmint

The changes in total phenolics, hydroxycinammic acid derivatives, and antioxidant properties of spearmint after five drying treatments (convection oven drying, freeze-drying, microwave drying, and air drying with the sun exposure and without the sun exposure) were investigated. Phenolic composition of dried spearmint was analysed by spectrophotometric assays, while DPPH radical scavenging activity and Ferric reducing/Antioxidant power (FRAP) assay was used to measure the antioxidant properties. The results showed that freeze drying produced dried spearmint that had the highest total phenolics (34.6 ± 1.9 mg/g) content and the most potent antioxidant capacity (126.2 ± 0.4 mg/g for FRAP and 88.1 ± 5.9 mg/g for DPPH, respectively). On the other hand, spearmint that was dried by convection oven and microwave drying presented the lowest amount of phenolic compounds (12.0 ± 0.5 mg/g) and antioxidant potency (49.3 ±0.7 mg/g for FRAP and 26.9± 1.6 mg/g for DPPH, respectively). This might be attributed to the fact that heat-sensitive phenolics were degraded or biotransformed at high temperatures. The loss of phenolic compounds and antioxidant activity reached up to 60% compared to freeze drying

Modeling approach for the air convective drying of leafy materials

Mathematical modeling in applied sciences could include predictive approaches in various unit operations of Chemical Engineering and/or Food Engineering. In air convective drying two key factors influence quantitatively and qualitatively the process and the processed material; temperature and air velocity. Although during the drying unit operation a severe shrinkage of leafy material occurs, no explicit account of this fact is taken in herb plant drying modeling. Even more rare, not to say un-existed, are applications of the true driving force, that is the thermodynamic driving force, according to the opinion of the authors. In this work both aspects have been considered and explicitly applied in the modeling of drying of a common herb plant, Mentha viridis, used as a model aromatic herb plant material. Furthermore, the study of synergistic or inhibitory effects between the influencing factors is presented. Application of the three before-mentioned aspects leads to interesting findings which are thoroughly discussed in the present paper