Antioxidant and Sensory Properties of Herbal Teas Formulated from Dried Moringa (Moringa Stenopetala) and Stevia (Stevia Rebaudiana Bertoni) Leaves

Herbal teas are gaining popularity and acceptance due to their sensory and health benefits. The demand for moringa tea currently increased in Ethiopia due to its nutritional and medicinal values. However, using moringa alone is difficult due to its poor sensory appeal and adding sugar to enhance the sensory has implications for health. The purpose of this study was to optimize the sensory properties (taste and aroma) of formulated herbal teas in addition to evaluating the antioxidant properties of the formulated herbal tea from dried moringa and stevia leaves. Seven moringa-based herbal teas were brewed with stevia ranging from 0 to 35% with five-level (5) and compared for their sensory and antioxidant properties. The moringa tea infusion and commercial green tea were considered as control. The results of sensory analysis showed that herbal tea brewed with 20-35% stevia in the formulation results in higher sweetness compared to 100%-moringa and green tea. Herbal tea brewed with 20-35% stevia in the formulation results in the highest in antioxidant (DPPH scavenging capacity, ferric reducing power and total antioxidant activities) values comparable to 100%-moringa. This study provides evidence that adding stevia to moringa improves the sensory and antioxidant properties without compromising its health-promoting compounds. Keywords: Moringa, stevia, phenolic content, antioxidant activity, herbal tea, sensory, herbal infusion. DOI: 10.7176/FSQM/102-01 Publication date: November 30th 202

Physico-Chemical Characteristics of Released and Improved Black Cumin (Nigella Sativa L.) Varieties

Black cumin (Nigella sativa L.) is an annual herb of the Ranunculaceae family, which is growing in Mediterranean region and Ethiopia. In Ethiopia the most people are used as household spice preparation and medicinal purpose. In Ethiopia, black cumin varieties are now days released, but there is no as such work on their physiochemical properties avail. This work presents the investigation of the physicochemical properties of the three-black cumin (Nigella sativa L.) verities (Derbera, Dershaye, and Edan). The results of physicochemical properties Derbera is highest in essential oil content (0.7%) and Edane is lowest (0.3%) than other verities and Dershaye is highest in refractive index of essential oil(1.49), refractive index of oleoresin( 1.52%), moisture(8.0%),fat(24.0%),ash(10.45%), protein(20.61%) and lowest in fiber(16.7%) content than other varieties. From this result, Dershaye black cumin Variety, verities show the superior quality in physicochemical properties than the two black cumin verities (Derbera and Edane)

Discrimination of Metallic and Colored Surface States by Optical Pattern Projection Method

Abstract In the optical pattern projection method called by the authors for surface roughness measurement, the roughness is detected from the qualities of the output image, such as contrast, formed by an imaging system including a target surface. We will report the relation between the roughness and contrasts for metallic surfaces and the colored plastics in the range of R a of about 0.1 µm and below, using a video camera. For the colored plastic surfaces, the authors explain that the sensitivity for gloss depends on the contrast of the formed image under additional illumination by other light sources

表紙・目次・ほか 39(1): 2014

publishe

Development of hybrid biphilic surfaces using a hydrophobic coating and laser texturing

V nalogi obravnavamo vpliv različno strukturiranih površin aluminija na izboljšanje prenosa toplote pri mehurčastem vrenju redestilirane vode v bazenu. Posamezne vzorce smo pripravili z različnimi kombinacijami laserskega strukturiranja in nanosa hidrofobnega premaza. Eksperimentalno smo ovrednotili vrenje na neobdelani površini, hidrofobni površini, dveh hidrofilnih površinah in štirih bifilnih površinah, ki smo jih obdelali z različnimi laserskimi parametri ter na dveh bifilnih površinah, ki nista imeli hidrofobnega premaza. Površine smo testirali na merilni progi za nasičeno vrenje v bazenu pri atmosferskem tlaku. Na merilni progi smo zabeležili vrelne krivulje do nastopa kritične gostote toplotnega toka (CHF) in iz njih izračunali koeficiente toplotne prestopnosti za posamezen vzorec. Pri analizi podatkov smo dobljene rezultate primerjali z referenčno površino (neobdelana aluminijasta površina). Vrednosti CHF so dosegale vrednosti med 890 kW/m2 in 1480 kW/m2. Najvišje vrednosti CHF in koeficienta toplotne prestopnosti so dosegale bifilne površine. Najvišja izmerjena vrednost CHF (1480 kW/m2) je predstavljala 30 % izboljšanje vrednosti CHF referenčne površine, kar pa je pomenilo zvišanje za 320 kW/m2. Zvišanje koeficienta toplotne pristopnosti pa je bilo 83 % in je tako dosegalo vrednosti 61,7 kW/m2K. Dokazali smo, da z lasersko strukturiranimi bifilnimi površinami lahko izboljšamo parametre vrenja v bazenu in s tem bistveno pripomoremo k izboljšanju prenosa toplote.In this work, we investigate the influence of aluminuim surfaces with different structures on enhanced pool boiling heat transfer of twice distilled water. Individual samples were modified by using different combinations of laser texturing and hydrophobization. An untreated surface, a hydrophobic surface, two hydrophilic surfaces and four biphilic surfaces textured with different laser processing parameters as well as two biphilic surfaces without a hydrophobic coating were experimentally tested. Surfaces were tested on saturated pool boiling experimental setup. Boiling curves up to the CHF values were measured and heat transfer coefficient was calculated. In the analysis, the results were compared with the reference surface (raw aluminium surface). CHF values reached values between 890 kW/m2 and 1480 kW/m2. The highest measured values of CHF and heat transfer coefficient were reached by biphilic surfaces (1480 kW/m2) which represent a 30 % improvement regarding to the reference surface. Heat transfer coefficient improvement reached up to 83 % and achieved the highest value at 61,7 kW/m2K. We have demonstrated that laser-structured biphilic surfaces can improve the pool boiling parameters and can significantly contribute to the improvement of boiling heat transfer