ANTIOXIDANT CAPACITY,SCAVENGING RADICAL ACTIVITY AND SELECTED CHEMICAL COMPOSITION OF NATIVE APPLE CULTIVARS FROM CENTRAL EUROPE

ABSTRACT

The main aim of this study was to focus on 10 typical native apple cultivars from Central Europe and to determine the basic characteristics such as dry matter, soluble solid content, titrable acidity, the content of pectins, phenolics, ascorbic acid, antioxidant capacity and the scavenging effect of 10% apple fruit extracts on hydroxyl radical, nitric oxide and superoxide radical in them. In our experiments, it was found out that the highest content of organic acids was shown by the “Jeptiska” cultivar (5.40 g/kg of FM). As far as the content of pectins was concerned, the highest levels were found out in the “Strymka” cultivar (32.60 g/kg FM). In case of total phenolic content, antioxidant capacity, ascorbic acid content and scavenging activity of reactive oxygen species (hydroxyl radical, nitric oxide and superoxide anion), high efficiency was determined in the local cultivars, namely, in “Matcino,”“Panenske ceske” and “Strymka.”

PRACTICAL APPLICATIONS

The results shown have wide use in the alimentary industry and human nutrition as apples belong to the most widespread core fruit. There exist many apple cultivars that have not been described in detail in literature and this study provides an insight into 10 not very common cultivars in the world; and although in Central Europe these cultivars are cultivated successfully, so far they have not been utilized commercially. However, their genetic uniqueness represents an irreplaceable ecological wealth and for that reason these local cultivars could become a new and outstanding source of nutrients and food. Today, they can also be used as a potential material for further breeding and selection.     

A COMPARISON BETWEEN TWO METHODS FOR THE RECOVERY OF LISTERIA MONOCYTOGENES IN MILK POWDER REFERENCE SAMPLES

Two methods (A and B) for the recovery of Listeria monocytogenes were compared using reference samples based on spray drying of milk containing this pathogen and competitive microflora. For method A, the sample was inoculated in a buffered liquid medium (same as IDF Pre-enrichment Broth) and then passed to IDF Enrichment Broth plus phosphate buffer. For method B, the sample was inoculated in FDA Enrichment Broth (LEB) and then passed to LEB (subenrichment). The solid selective medium used in both cases was Listeria Selective Agar (Oxford formulation). The sensitivity and specificity of method B was 95.2% and 100% vs. 76.1% and 88.8% for method A, respectively.     

Assessment of chitosan and extracts of lemon and sage as natural antimicrobial agents during Fior di latte cheesemaking

The use of antimicrobial active compounds (chitosan, lemon and sage extract) in Fior di latte cheesemaking was assessed. The three agents were added at different concentrations during processing cow’s milk. Control cheese was also made without active compounds. All cheese samples were kept at 4°C for 7 days and investigated for sensory and microbiological properties. Results clearly showed that the addition of lemon extract and chitosan increased cheese shelf life. In particular, the highest increase (129%) was recorded by adding 1000 mg/kg of lemon. In contrast, the addition of sage extract negatively affected the sensory properties, thus making the cheese unacceptable.     

Imaging applications of synchrotron X-ray phase-contrast microtomography in biological morphology and biomaterials science. I. General aspects of the technique and its advantages in the analysis of millimetre-sized arthropod structure

Synchrotron‐generated X‐rays provide scientists with a multitude of investigative techniques well suited for the analysis of the composition and structure of all types of materials and specimens. Here, we describe the properties of synchrotron‐generated X‐rays and the advantages that they provide for qualitative morphological research of millimetre‐sized biological organisms and biomaterials. Case studies of the anatomy of insect heads, of whole microarthropods and of the three‐dimensional reconstruction of the cuticular tendons of jumping beetles, all performed at the beamline ID19 of the European Synchrotron Radiation Facility (ESRF), are presented to illustrate the techniques of phase‐contrast tomography available for anatomical and structural investigations. Various sample preparation techniques are described and compared and experimental settings that we have found to be particularly successful are given. On comparing the strengths and weaknesses of the technique with traditional histological thin sectioning, we conclude that synchrotron radiation microtomography has a great potential in biological microanatomy.     

Knockdown of apoptosis-inducing factor disrupts function of respiratory complex

Recent findings suggest that apoptotic protein apoptosis-inducing factor (AIF) may also play an important non-apoptotic function inside mitochondria. AIF was proposed to be an important component of respiratory chain complex I that is the major producer of superoxide radical. The possible role of AIF is still controversial. Superoxide production could be used as a valuable measure of complex I function, because the majority of superoxide is produced there. Therefore, we employed superoxide-specific mitochondrial fluorescence dye for detection of superoxide production. We studied an impact of AIF knockdown on function of mitochondrial complex I by analyzing superoxide production in selected cell lines. Our results show that tumoral telomerase-positive (TP) AIF knockdown cell lines display significant increase in superoxide production in comparison to control cells, while a non-tumoral cell line and tumoral telomerase-negative cell lines with alternative lengthening of telomeres (ALT) show a decrease in superoxide production. According to these results, we can conclude that AIF knockdown disrupts function of complex I and therefore increases the superoxide production in mitochondria. The distinct effect of AIF depletion in various cell lines could result from recently discovered activity of telomerase in mitochondria of TP cancer cells, but this hypothesis needs further investigation     

ALPHA-LINOLENIC ACID AND LINOLEIC ACID IN SERUM AND TISSUES AFTER FLAXSEED (Linum usitatissimum) OIL IN VIVO ADMINISTRATION

Essential fatty acids can be helpful in the prevention of several pathologies. The bioavailability of acute supplementation of different doses of flaxseed oil was studied by analyzing the level of alpha-linolenic acid (ALA) and linoleic acid (LA) in serum and tissues (adipose, liver) of rats tested at 2, 4, 8 and 16 h after the administration. The amount of flaxseed oil administered at increasing doses corresponded to 1, 2.5 and 5 g ALA/kg of body weight. The corresponding fatty acid methyl esters obtained via direct methylation were quantified using gas chromatography/mass spectrometry. Serum ALA level increased after 1 or 2.5 g/kg. ALA was increased in both adipose and liver tissue 4 h after the administration of 1 g/kg of flaxseed oil. There was no further increase by using a higher oil dosage. LA did not change in serum at the doses used.

PRACTICAL APPLICATIONS

The bioavailability of acute supplementation of increasing doses of flaxseed oil was examined by analyzing the level of alpha-linolenic acid (ALA) (ω3) and linoleic acid (ω6) in serum and tissues (adipose, liver).These data suggest that there is a limiting step in the absorption of these fatty acids and that there is no advantage to take more than 1 g/kg of ALA supplementation. The daily use of flaxseed oil could be a good alternative in some cases to fish oil in the prevention of several pathologies.