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

The Potential of Sun-Dried Grape Pomace as a Multi-Functional Ingredient for Herbal Infusion: Effects of Brewing Parameters on Composition and Bioactivity

Wine and by-products are essential elements of a Mediterranean diet and considered as a reservoir of bioactive compounds with various health effects. Grape pomace, an easily available natural material of low cost, shares a similar wealth of health benefiting bioactive phytochemicals. The objective of this study was to explore the utilization of grape pomace from Commandaria dessert wine as main ingredient for functional infusions. Therefore, the ratio of water to grape pomace powder (40–200 mL g−1), infusion time (3–15 min) and temperature (55–95 °C) were optimized in terms of composition and bioactivity. Multiple response optimization indicated that brewing 200 mL water per g of material for 12.2 min at 95 °C, was the optimum method for preparing the infusion. Results also revealed a significant impact of three parameters as well as quadratic and interactive effects on composition and bioactivity of infusions. Furthermore, the infusion presents antimicrobial effects against Listeria monocytogenes serotypes and other common food pathogenic bacteria. Finally, a sensory evaluation was performed to assess the organoleptic attributes of the infusion and its improvement, with the addition of Mediterranean aromatic plants. Overall, the present work describes a promising strategy for the re-use of sun-dried grape pomace as a functional ingredient of infusions

Evaluation the enzyme inhibitory properties of Commandaria grape pomace extracts associated with hyperglycemia

The grape pomace contains plethora of polyphenols as phenolic acids, flavanoids, anthocyanins, tannins and stilbenes, which are linked with diverse health effects. Many studies manifest that grape phenolics exert potent anti-hyperglycemic effects. The α-amylase and α-glucosidase inhibitory effects are considered as a possible mechanism of their action. Commandaria is a dessert wine, which is produced by wine-making sun-dried grapes. Thus, its pomace comprises high concentration of polyphenols due to dehydration. The objective of this work was to evaluate grape pomace phenolics as potential enzyme inhibitors related with hyperglycemia. Therefore, the effect of extraction systems (methanol 100%, methanol-water 80 – 20%, methanol-water 60 – 40%, ethanol 100%, ethanol-water 80 – 20%, ethanol-water 60 – 40%, acetone, acetone-water 80 – 20%, and acetone-water 60 – 40%) on the bioactive composition and enzyme inhibitory properties was studied. Results demonstrated that ethanolic and hydroethanolic grape pomace extracts had the highest phenolic and hydroxycinnamate contents followed by methanolic and hydromethanolic extracts. Acetone and its aqueous mixtures also recover higher amounts of flavanols compared to alcohols. Furthermore, results showed the α-amylase and α-glucosidase inhibitory activities of Commandaria grape pomace extracts were strongly affected by extraction system. The a-amylase and a-glucosidase inhibitory effects (IC50) ranged from 19.1 ± 0.8 to 27.6 ± 1.4 µg · mL−1 and from 70.4 ± 4.9 to 88.9 ± 6.7 µg · mL−1, respectively. The findings suggest the use of pure alcohols and methanol-water (80 – 20%) to prepare extracts with potent enzyme inhibitory activities. Overall, the current study highlights the Commandaria grape pomace as inhibitors of α-glucosidase and α-amylase and provides a knowledge-base for the selection of the most appropriate solvents to produce antihyperglycemic extracts

Commandaria Sweet Wine Melanoidins as Functional Food Ingredient: Exploring Antioxidant, Antimicrobial and Anti-hypertensive Potential.

Background & aims: Melanoidins are high molecular-weight, brown-colored and nitrogen-containing compounds generated in the late stages of the Maillard reaction. These compounds are mainly responsible for specific color and typical appearance of thermally processed foods. The aim of this work was to study the functional properties of the melanoidins isolated from Commandaria, a straw sweet wine

Dynamic changes in targeted phenolic compounds and antioxidant potency of carob fruit (Ceratonia siliqua L.) products during in vitro digestion

Carob fruit is considered as a rich source of phenolics that are linked with potent health effects. The aim of this work was to study the effect of a triple-step digestion on the stability of phenolics and antioxidant potency in carob products. Results showed that the gastric and intestinal steps induced the most significant changes in the stability of pure phenolics; their recovery ranged between 61 and 88% at oral, 40–87% at gastric and 16–57% at intestinal step. Regarding to the carob products, the yield of phenolic contents were ranged from 0.83 to 1.41 for gastric and from 0.43 to 0.82 for intestinal phase. The counterpart yield of antioxidant potency was 0.84–1.66 and 0.48–0.67, respectively. HPLC analysis also disclosed interesting findings; the stability of phenolics is strongly influenced by their chemical structure. In general, the phenolic acids are quite resistant under digestion procedure, whereas the flavonols are mostly degraded when they were subjected into digestion. Results points out that the carob phenolics are degraded, released from food matrix or attached to other food or digestive juice constituents. Furthermore, the critical role of food matrix was underlined as the food components had a protective effect against pH changes and enzymatic activities along digestion