ISSN 2285-1364, ISSN CD-ROM 2285-5521, ISSN ONLINE 2285-1372, ISSN-L 2285-1364
 

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Priyanka MALIK*, Sabine DANTHINE, Aman PAUL, Christophe BLECKER

Fat globules in milk are present in form of emulsion stabilized by milk fat globule membrane (MFGM) which originates in mammary gland. Buttermilk which is rich source of MFGM finds application as an ingredient in dairy and food industry (emulsions, infant formulas & low fat products) for its emulsifying and stabilizing properties which are associated to polar lipids. Phospholipids & some proteins have also shown some medicinal properties. So, MFGM received much attention in recent years due to its health-beneficial & technological properties. This work has been carried out with the objective to characterize MFGM at different stages of extraction. MFGM fractions were isolated from fresh cream and collected at different steps during processing to study its physical-chemical characterization. The fractions were characterized for their chemical composition to have an idea at which stage which components are isolated. The sample were also characterized for their surface properties which included study of mechanical properties of monolayer using Langmuir film balance, surface tension and zeta potential. Physical-chemical studies of fractions suggest that each fraction of MFGM have different chemical composition and surface properties which could be of interest for use in different food products depending on the requirement. The choice of these fractions could be done for their use as food additive/ingredient in food industry depending on the application. It may even have an extended application in pharmaceutical industry.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Steliana DOBRE, Aurel GIURA

The paper highlights the role and importance of plant growth regulators (PGR) application before or post pollination with regard to embryo formation and haploid plant regeneration in wheat-maize hybridization. The efficiency of some PGR combinations (doses, procedures, time of application) and genetic influence on some parameters characterizing the efficiency of haploid production at NARDI Fundulea are briefly described. Taking into account the decreasing efficiency, in the last period, the need for new and different variants of PGR are discussed.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Ivan IVANOV, Nadezhda PETKOVA, Panteley DENEV, Atanas PAVLOV

Fragaria vesca L. (wild strawberry) belongs to the Rosaceae family. The leaves and roots from wild strawberry are herbal materials applied in traditional medicine. Fragaria vesca are rich source of biologically active substances like tannins, procyanidins, anthocyanidins, flavonoids and phenolic acids. The aim of this study was to compare the value of phytochemical compounds and antioxidant activities in infusion and decoction obtained from the wild strawberry leaves. The extracts were analyzed regarding their secondary metabolite content (total polyphenols, total flavonoids and total proanthocyanidins) and antioxidant activities (DPPH and CuPRAC methods). The analysis of decoction extracts from the leaves harvested in blooming period revealed the highest level of total polyphenols (46.1 mg GAE/g DW), total flavonoids (4.7 mg QE/ g DW), total proantocyanidines (22.3 mg/ g DW) and antioxidant activities – radical scavenging activity (DPPH – 325.0 mM TE/ g DW) and metal reducing ability (CuPRAC – 1257.9 mM TE/ g DW). The results showed that the water extracts from leaves of Fragaria vesca are appropriate additives for preparation of functional foods and natural cosmetic products with improved biological activity.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Andreea STAN, Mona Elena POPA

Recently, for increasing fruits shelf life, food industries used thermal processing, which has been shown in some studies to affect the sensorial and physic-chemical properties of these products. During smoothie production is mandatory to have raw materials for the whole year, so it is necessary to storage it after different pretreatments such as freezing. Color, flavor, texture and physic-chemical properties of food products have an important role in correlation with taste, sensory perception and consumer acceptance. These are critical quality attributes affecting the acceptability of fruits, fresh, frozen or processed (concentrates, jam, juice, nectar, syrup, dairy products), thus being of major concern in product design. Strawberries are popular fruit with high visual appeal and desirable flavor, but are highly perishable, being susceptible to mechanical injury, water loss, decay and physiological deterioration. The natural color of strawberries and their products easily fades or deteriorates during processing and storage. The aim of this study is to observe the influence of freezing storage on color, texture, antioxidant activity, vitamin C and physic-chemical properties of strawberry and strawberries puree. For this purpose, were realized and analysed 4 different samples starting with just harvested strawberries, pressed strawberries, strawberries immersed in ascorbic acid 1% for 5 minutes and strawberries blanched at 950C for 5 minutes, before and after freezing. These purees were stored for 6 months in the freezer. During frozen storage the lightness index, L, yellowness index, b and the redness index, a, were also measured and it was observed colour changes for all of strawberry samples. pH and acidity values, showed that the strawberry samples registered insignificant changes compared to standard (control) samples.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Silvana-Mihaela DĂNĂILĂ-GUIDEA, Ricuţa-Vasilica DOBRINOIU, Luminiţa VIŞAN, Radu Cristian TOMA

The plant known scientifically as Lycium barbarum L., and commonly in the West as the wolfberry, or simply as "goji", is considered by many authors as the most nutrient rich plant on earth. It has been used for thousands of years by Chinese and Tibetan therapists as a source of health. The plant Lycium (Goji) is a shrub of the family Solanaceae is a true national treasure for China used in traditional medicine for over 2000 years.Thus, according to information published in various specialized articles and those taken from traditional beliefs, goji fruit is considered to be an important antioxidant, antidiabetic, and a natural source with excellent effects on the cardiovascular system and in decreasing the level of cholesterol in the human body. Given the properties of this imported super fruit the initiative to develop a propagation protocol to be widely used in Romania too is therefore considered to be one relevant for this plant species. The direct organogenesis protocol used in this study yields explants and microcuttings from meristematic apexes consisting of 2-3 node fragments detached from 30 day old goji seedlings germinated in in vitro conditions. The average was 89-95% for morphogenetic culture; for the offshoots rooted in a liquid culture supplemented with 1 mg / l IBA, it was 100% .In vitro goji rooted plantlets were successfully acclimatized (average survival rate of 90-98%) in a peat substrate mixed with sand. After being placed under ex vitro conditions, the vitroplantlets increased rapidly and developed well. Over a period of one month, they formed new branched roots and many axillary shoots with healthy leaves.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Aman PAUL, Michel FREDERICH, Roel UYTTENBROECK, Sandrino FILOCCO, Séverin HATT, Priyanka MALIK, Arnaud MONTY, Frederic FRANCIS, Christophe BLECKER, Sabine DANTHINE

Field border flowering strips are commonly grown throughout the world mainly to enhance biodiversity. However besides their basic function they can also yield numerous compounds which could be interesting for wide range of industries such as food, pharmaceutical, etc. With the aim of valorization, proximate compositional analysis of seeds from some commonly grown flowering strips: Galium verum, Hypericum perforatum, Leontodon hispidus, Lotus corniculatus, Lythrum salicaria, Origanum vulgare and Trifolium pratense was realized. The protein content of residue left after the lipid extraction was also determined for exploring possibilities of its utilization as a protein source. Results suggest that seeds from some of these plants can be a potential source to render food compounds.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Mioara NEGOIȚĂ, Gabriel MUSTĂȚEA, Enuța IORGA, Alina ADASCĂLULUI, Giuseppe SPADARO, Nastasia BELC, Luminița CATANĂ, Andreea STAN

The influence of the dough preparation process on the acrylamide level formed in different bread types was studied. For each preparation process – direct (PD) and indirect (PI), four types of bread: "Pan bread", "Simple bread stick", "Olive bread stick" and "Onion bread stick" were obtained.Water content, acrylamide level and chromatic parameters, CIELab (L*, a*, b*) for each type of bread were measured. Acrylamide analysis was performed by GC/MS/MS-SRM, by using the internal standard method of labelled acrylamide (1,2,3-13C), min. 99% purity.The results show that, acrylamide level obtained for the bread samples prepared through PI process is lower than the acrylamide level obtained for the bread samples prepared through PD process. Preparation of dough through PI process decreases the acrylamide level, in all tested samples, with 6.29% to 31.63% compared with the PD process.Regarding color parameters (L*, a*, b*), samples obtained through both PD and PI process, had similar variations. Also it was found no correlation between CIELab color parameters and the level of acrylamide.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Tsvetanka TENEVA-ANGELOVA, Dora BESHKOVA

It was examined the possibility for growth of representatives from genera Enterococcus and Streptococcus, isolated from different parts of the herbs Salvia and Geranium in the presence of relevant crude plant extracts. There have been established relationships between the type and concentration of the herbal extracts and tested microorganisms. It was determined a resistance profile of examined lactic acid bacteria against the effect of natural plant extracts. It was established that Streptococcus thermophilus and Enterococcus faecium (isolated from Geranium) grow in the presence of extract of Geranium sanguineum L. in concentrations up to 30 mg/ml whereas some strains S. thermophilus and Ent. faecium (isolated from Salvia) show higher resistance - in range of 30 mg/ml to 100 mg/ml extract of Salvia officinalis L. This is an evidence of selective inhibitory activity of plant extracts to examined lactic acid bacteria and it is a prerequisite for their incorporation in food fermentation that have a lot of economic value, as well as in helping improve human health.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Ivanka PETROVA, Kremena NIKOVSKA, Biser BENOV

There are many hydrocolloids that are used as thickening agents in food emulsions and improve their quality and shelf life. Flaxseed is one of the healthy grains that could be used in functional foods development. The objective of this work was to evaluate the effect of flaxseed gum concentration and temperature on the rheological properties of oil-in-water (O/W) emulsions with flaxseed gum (FG). FG solution and O/W emulsions with different hydrocolloids were prepared. The rheological behavior of the samples was determined, the flow behavior index (n) and a consistency index (k) values were assayed. The emulsions containing the greatest percentage of gums presented higher viscosity than the reference emulsions. This study shows a good potential of flaxseed gum to be used as a thickening agent in O/W emulsions.

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Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XIX
Written by Diana GROPOŞILĂ-CONSTANTINESCU, Ovidiu POPA, Narcisa BĂBEANU, Gabriela MĂRGĂRIT

Among hundreds species of yeasts and molds, only few are able to accumulate more than 25% lipids. The aim of our experiments was to select microorganisms with high potential of lipids producing (“oleaginous” microorganisms). Several strains of yeasts and molds were tested in order to determine their ability to produce and accumulate lipids. The strains were cultivated in Petri dishes on specific media. Evaluation of lipid accumulation was achieved by microscopic observations, through Sudan Black B dyeing technique. Preliminary tests in order to determine the capacity of lipid production were made by Soxhlet extraction, after batch fermentations on liquid media. The results showed that five strains of yeasts and molds, Yarrowia lipolytica, Hansenula anomala, Sacharomyces cerevisiae, Aspergillus niger and Trichoderma viridae, were the best lipid producers, which accumulated up to 40% of lipids in dry biomass. One of the key factors in achieving an economically attractive bioprocess is the conversion yield of the substrate into lipids. In this case, yeasts are superior to fungi with a conversion yield over 20%, in comparison with less than 18% for molds. Given these considerations, additional experiments will be conducted to optimize the conditions of lipid production with Yarrowia lipolytica.

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