Volume 19, No. 4 (2018)
Articles
PROCESSING SLIME FROM SNAIL (HELIX ASPERSA MAXIMA): A PRELIMINARY STUDY ON THE EFFECT ON MICROBIAL LOAD
RAQUEL TEIXEIRA(1), JOANA BARBOSA(1), HELENA ALBANO(1), CLÁUDIA MACIEL(1), JOANA SILVA(1), JORGE A. SARAIVA(2), SÓNIA M. CASTRO(1,2), PAULA TEIXEIRA(1*)
Slime from earth snails (Helix aspersa maxima) is a sub-product often used in the cosmetic industry. Due to its origin, a decontamination process ought to be considered. After exposure to UV radiation, no significant (P > 0.05) reduction of the initial microbial load of slime was observed, while treated at 60 °C, a decrease of 4.0 log CFU∙mL-1 was obtained (when compared to non-treated slime). A similar reduction was attained for pressurized (500 MPa) slime. The sequential combination of temperature and pressure treatment had a similar effect (P > 0.05) on the microbial load when compared to 400 MPa (30 min), but the reduction was higher when compared to the less intense treatments (60 °C, 15 min; 400 MPa, 15 min). Overall, the results suggest that pressure ( 400 MPa) is a promising technology for processing snail slime, which can have positive effects on its microbial load, for further use in the cosmetic industry.
ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY CHARACTERIZATION OF KITCHEN UTENSILS USED AS MATERIALS FOR LOCAL COOKING IN TWO CULINARY MEDIA
JACQUES SAWADOGO(1*), MOUSSA BOUGOUMA(3), AMINATA KABORE(1), DASMANE BAMBARA(1), JEAN BOUKARI LEGMA(2)
This study is inscribed in the framework of the valorization of traditional kitchen utensils recycled from aluminum waste in Burkina Faso. In fact, these traditional kitchen utensils made of recycled aluminum alloys occupy a very important place in Burkina Faso’s kitchen. The effect of foods for consumption on its local utensils was studied using the non-stationary technique and electrochemical impedance spectroscopy. For this purpose, a sample of utensil has been deducted on traditional production site. The corrosion behavior of the recycled aluminum alloy ok know chemical composition was evaluated by analyzing the impedance spectra obtained at the open circuit potential, in the salt media titrated at 3 g·L-1 and rice. Modeling electrical properties by the using of a simple equivalent circuit made it possible to interpret the results obtained by impedance spectroscopy. The results showed a susceptibility to pitting corrosion and were confirmed by the electrochemical impedance spectroscopy method.
PRODUCTION OF SILVER NANOPARTICLE FROM CHLORELLA VULGARIS AND DUNALIELLA SALINA
HERMIN P. KUSUMANINGRUM(1*), MUHAMMAD ZAINURI(2), INDRAS MARHAENDRAJAYA(3)
Green microalgae have advantages as they are easily available, grow rapidly and produce various secondary metabolites including carotenoids, fatty acids, proteins and lipids. Synthesis of nanosilver microalgae C. vulgaris and D. salina offers environmental antimicrobial and biomedical agent. The objective of this study was to produce silver nanoparticle (SNP) microalgae using C. vulgaris and D. salina as an eco-friendly antimicrobial agent. This research method was conducted by synthesizing silver nanoparticle microalgae using C. vulgaris and D. salina along with characterization under UV–visible spectroscopy, transmission electron microscopy (TEM), and scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDX). The results showed that SNP of C. vulgaris and D. salina microalgae could be produced using agitation treatments. The synthesized AgNPs C. vulgaris and D. salina exhibited maximum absorption at 398 nm, and EDX analysis had determined that the abundance of chemical elements presented in the sample is carbon (53 %) and silver (32 %). TEM analysis revealed that they had spherical form with a size of 9.3 nm. The spot of EDX analysis shows the presence of silver atoms in both microalgae. SEM analysis shows a spherical shape with an average size of 50 nm with several silver particles in the cell. These results indicate that the formation of SNP using C. vulgaris and D. salina microalgae has been successfully obtained under agitation treatment.
EFFECT OF PRE-TREATMENT AND AIR TEMPERATURE ON DRYING KINETICS AND QUALITY OF JERUSALEM ARTICHOKE
İBRAHIM DOYMAZ*
The effect of pre-treatment and air temperature on the drying kinetics and some quality criteria of Jerusalem artichoke were investigated. The pre-treated and untreated of Jerusalem artichoke slices were dried in a cabinet dryer at temperatures of 60, 70 and 80 °C. It was found that air temperature and pre-treatment had more significant effects on drying kinetics, color and rehydration ratio. The experimental data were adjusted to seven thin-layer drying models in the representation of vegetable and fruit drying. The Midilli & Kucuk model was best fitted to measurements. The effective moisture diffusivity at each temperature was determined by Fick’s second law of diffusion, in which their value varied from 5.49×10–10 to 1.90×10-9 m2·s-1 over the mentioned temperature range. The values of the activation energy of moisture diffusion were 50.74 and 40.21 kJ·mol-1 for citric acid and control samples, respectively.
DETERMINATION OF POLYPHENOLS CONTENT, ANTIOXIDANT AND ANTIBACTERIAL ACTIVITY OF NIGELLA SATIVA L. SEED PHENOLIC EXTRACTS
OMAR MECHRAOUI(1*), SEGNI LADJEL(2), MED SAID NEDJIMI(2), MOHAMED LAKHDAR BELFAR(2), YOUNSE MOUSSAOUI(3)
In this work, we studied the phenolic extracts of the seeds of Nigella sativa L., from the point of view of the chemical composition and the antioxidant activity. The extraction of polyphenols was carried out using two different solvent systems, namely methanol: water 7: 3 (v / v) and acetone: water 7: 3 (v / v). The qualitative and quantitative analysis of methanolic and acetonic extracts by HPLC (High Performance Liquid Chromatography) revealed the presence of gallic acid, apigenin, naringenin, rutin, quercetin and kaempferol. The quantification of total phenols by Folin-Ciocalteu colorimetric method and flavonoids by the AlCl3 method gave higher values with the methanolic extracts compared to the acetonic extract. The total polyphenol content of the methanolic extract 1.3714 ± 0.0315 mg/g (mg GAE / g dw) is more elucidated than the content in acetone extract 0.5962 ± 0.0046 mg/g (mg GAE/g dw). The evaluation of the antioxidant power of the phenolic extracts was made by two chemical tests namely the DPPH test and the β-carotene bleaching test and we finished this work by studying the antibacterial and antifungal activity of these phenolic extracts.
COMPARATIVE STUDY REGARDING THE EFFICIENCY OF SOME COMMERCIAL LACTIC STARTERS FROM THE ROMANIAN INGREDIENTS MARKET FOR BAKERY INDUSTRY
MARIA S. CHIȘ, ALINA STURZA, ADRIANA PĂUCEAN*, SIMONA MAN, VLAD MUREȘAN, ANAMARIA POP, SEVASTIŢA MUSTE
Sourdough influences in a good way all aspects of the bakery products quality. Sourdough fermentation has gained the worldwide attention due to its positive influence on sensorial, textural, nutritional and shelf life of baked goods. For this work, four commercial starter cultures were selected, in order to assess their influence on products quality. The major lactic bacteria in the starter cultures were: Lactobacillus brevis, Lactobacillus sanfrancisco and according the producer, specific facultative hetero-fermentative lactic strains. The obtained sourdoughs, fermented according to their supplier specifications, were added to wheat dough at 5 - 30 % amount level. The starters’ performance was assessed in 2 stages protocol. Firstly, all starters were assessed by analysing the results of physico-chemical and sensorial properties. In the second stage, three starters were selected and the protocol was performed again. Physico-chemical analyses (porosity, elasticity, H/D, L/w, acidity) were performed according to SR 91/2007. Aroma profile and sensory analysis were assessed using a hedonic test. All starter cultures showed good performance on improving the bread quality in the conditions of this experiment, differences could be noticed in relation to textural and sensorial properties.
THE INFLUENCE OF AIR VELOCITY ON THE BEHAVIOR OF A SOLID PARTICLE DISPLACEMENT IN A VERTICAL PATH
EMILIAN MOȘNEGUȚU, VALENTIN NEDEFF, NARCIS BÂRSAN*, DRAGOȘ RUSU
This article presents an experimental study regarding the behavior of a ball-shaped polyethylene solid particle in vertical air channel. To this effect, we used a laboratory stand, an aerodynamic screen with vertical air flow, and a high-speed camera to study the behavior of the solid particle. The recoding speed of this measurement was 500 frames∙sec-1. During this assessment, the movement direction of the solid particle within the vertical air flow was not taken into account, i.e. the particle moved either in the same direction with the air flow or in the opposite direction. After the video recording analysis, a series of physical data of the solid particle have been identified, such as: average travelling speed, distance covered by the solid particle, tracing time, angular speed of the solid particle and its rotation. It has been observed that aforementioned data are in strict accordance with the variation of the speed of the air flow passing through the ascending vertical air channel.
KINETICS OF THE HYDROLYSIS OF CASSAVA STARCH BY GLUCOAMYLASE AND A GRANULAR STARCH HYDROLYZING ENZYME
HARGONO HARGONO*, BAKTI JOS, ANDRI CAHYO KUMORO
Kinetic studies of the enzymatic hydrolysis of cassava starch have been carried out using glucoamylase and granular starch hydrolyzing enzyme (GSHE) as StargenTM 002. The enzymatic hydrolysis of cassava starch was conducted at pH 4 by employing slurry concentrations of 25-300 g·L-1, temperatures 30-60 C and 0.5-1.5 % (w/w) of enzymes glucoamylase and StargenTM 002. Higher temperatures accelerated the enzymatic reaction using glucoamylase, while the similar effect levelled of at 40 °C for hydrolysis using StargenTM 002. The cassava starch concentrations of 200 and 250 g‧L-1 were found as the critical substrate concentrations for lower (glucoamylase 0.5 and 1 %) and higher (glucoamylase 1.5 %) enzyme concentrations used, respectively. Based on the Lineweaver-Burk plot for cassava starch hydrolysis using glucoamylase, the maximum reaction rates, Vmax for 0.5, 1.0 and 1.5 % (w/w) glucoamylase were 3.55, 5.78 and 9 g‧L-1‧h-1, while the Michaelis-Menten constants, Km were 140.35, 140.75 and 152.10 g‧L-1. Accordingly, the maximum reaction rates, Vmax for 0.5, 1 and 1.5 % (w/w) of StargenTM 002 were 7.19, 11.6 and 18.18 g‧L-1‧h-1, respectively. While the Michaelis-Menten constants, Km obtained at those enzyme concentrations were respectively 160.86, 161.31 and 160.85 g‧L-1. It is an indication that the rate of starch hydrolysis using StargenTM 002 is faster than glucoamylase.
ANALYSIS OF WATER QUALITY FOR TWO RIVERS LOCATED NEAR A MINING AREA
ALINA COCHIORCA(1), VALENTIN NEDEFF(1,2), NARCIS BÂRSAN(1*), EMILIAN FLORIN MOȘNEGUȚU(1), MIRELA PANAINTE-LEHĂDUȘ(1), CLAUDIA TOMOZEI(1)
The paper presents a study that was focused on the analysis of the existence of metals in the rivers located near the salt mine Targu Ocna, Romania. The points identified near mining areas and the proposal for performing analyzes regarding the presence of metals in surface waters are the Slanic River and the Trotus River. The purpose of this study is to analyze the physico-chemical parameters: (pH, electrical conductivity, dissolved oxygen, turbidity, temperature), selected heavy metals (Fe, Mn, Zn, Cr), Mg and Al of the Slanic River and the Trotus River located near the salt mine and to investigate the level of metal contamination due to mining activities. The samples were collected at two points in the Slanic River and two points for the Trotus River. The physico-chemical parameters were measured in-situ with portable equipment and within the Water Analysis Laboratory of “Vasile Alecsandri” University of Bacau. The values registered for the physico-chemical parameters were compared with the permissible limits by the legislation.
INFLUENCE OF PLEUROTUS OSTREATUS β-GLUCANS ON THE GROWTH AND ACTIVITY OF CERTAIN LACTIC ACID BACTERIA
M.S. KOKINA(1), M. FRIOUI(1), M.M. SHAMTSYAN(1*), V.S. SIBIRTSEV(2), L.V. KRASNIKOVA(2), V.G. KONUSOVA(3), A.S. SIMBIRTSEV(3)
Over the last few decades, polysaccharides of fungi, namely beta-glucans captivated researchers' attention for they hold many significant properties; the most important ones are immunomodulating and antitumor properties. Although, beta-glucans are widely represented in nature, the most biologically active form of beta-glucans is beta-1,3 / 1,6-glucan. Most often, this type of beta-glucans is found in some yeast, bacteria, and mycelial fungi. Thus, in recent years, fungi have been the focus of scientists around the world as a source of biologically active compounds with beneficial effects on human health. Some fungi and derived from them biologically active substances were included in the product group, defined as "functional foods", i.e. as food, whose health benefits were documented by scientific research and whose beneficial effects can not be attributed only to the availability of nutrients. The use of functional foods containing beta-glucans leaves no doubt. With the aim of imparting new properties to functional fermented products by introducing into their composition beta-glucans of fungal origin, the effect of water-soluble beta-glucans obtained from the deep mycelium of oyster mushroom (Pleurotus ostreatus) on the activity of lactobacillus bacteria (Lactobacillus acidophilus, Streptococcus salivarius subsp., thermophilus, Lactobacillus bulgaricus).