Evaluation of Fruit Extracts Influence on the Susceptibility of Escherichia Coli Rods to the Bactericidal Action of Human Serum

This study determined the influence of the methanol (ME) and water (WE) fruit extracts obtained from eight species of Rosaceae and Grossulariacae family on the susceptibility of Escherichia coli rods to the lytic action of normal human serum (NHS). Bacteria were incubated for 24 h in tryptic soy broth with varying concentrations (1, 5, 10, 20, 30, 40, and 50 mg ml-1) of raspberry, cherry, hawthorn, dog rose, gooseberry, chokeberry, quince, and Japanese quince extracts and then the bactericidal activity of NHS was established. We found that the resistance of E. coli rods to the bactericidal action of serum was altered by prior incubation with all tested extracts and was dependent on plant extract concentration. Among the tested extracts, gooseberry (both ME and WE), raspberry ME and cherry WE were responsible for the most profound changes in serum resistance of E. coli rods. Evaluation of the antimicrobial mechanisms of action of phenolics-rich plant extracts has the potential to impact the development of novel compounds with promising applications in food and biopharmaceutical industry or medical approaches to preventing and treating pathogenic infections.

Investigation of Phenolic Composition and Anticancer Properties of Ethanolic Extracts of Japanese Quince Leaves

Glioblastoma multiforme is an aggressive and invasive disease with no efficient therapy available, and there is a great need for finding alternative treatment strategies. This study aimed to investigate anticancer activity of the extracts of the Japanese quince (JQ) cultivars ‘Darius’, ‘Rondo’, and ‘Rasa’ leaf extracts on glioblastoma C6 and HROG36 cells. As identified by ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry, the extracts contained three prevailing groups of phenols: hydroxycinnamic acid derivatives; flavan-3-ols; and flavonols. Sixteen phenols were detected; the predominant compound was chlorogenic acid. The sum of detected phenols varied significantly between the cultivars ranging from 9322 µg/g (‘Rondo’) to 17,048 µg/g DW (‘Darius’). Incubation with the extracts decreased the viability of glioblastoma HROG36 cells with an efficiency similar to temozolomide, a drug used for glioblastoma treatment. In the case of C6 glioblastoma cells, the extracts were even more efficient than temozolomide. Interestingly, primary cerebellar neuronal-glial cells were significantly less sensitive to the extracts compared to the cancer cell lines. The results showed that JQ leaf ethanol extracts are rich in phenolic compounds, can efficiently reduce glioblastoma cell viability while preserving non-cancerous cells, and are worth further investigations as potential anticancer drugs.

Physical and Sensory Properties of Japanese Quince Chips Obtained by Osmotic Dehydration in Fruit Juice Concentrates and Hybrid Drying

Japanese quince has high health value, but due to its taste and texture, it is difficult to eat raw. The use of innovative drying methods to produce dried snack foods from these fruits may be of interest to producers and consumers. The physicochemical and sensory properties of 3 mm slices of Japanese quince fruit (with skin, without seeds) obtained by osmotic pre-treatment in chokeberry and apple juice concentrates, and with the use of convection (convective drying, C-D), freeze-drying (F-D), and convection-microwave-vacuum drying (hybrid) are assessed. The methods of drying osmo-dehydrated slices do not affect the dry matter content. In most dried quince, the water activity is 0.40 or lower. Pre-osmotic dehydration and drying have a significant impact on the mechanical and acoustic properties of quince chips. Sensory attractive chips emit loud acoustic emission (AE) during the breaking test. Chips that are osmo-dehydrated in a mixture of chokeberry juice concentrate and sucrose and dried by a hybrid method are attractive. They have a dark red color given by chokeberry concentrate and a slight sweet (with a slight sour-bitter) taste. The sensory evaluation was useful for determining the quality of the chips in terms of their texture (crispness) tested by mechanical methods. Their sensory ratings (overall desirability as weight of color, taste, crispness, and flavor) are high and similar (from 3.8 to 4.1). The use of innovative drying methods with pre-osmotic treatment allows obtaining dried material with properties comparable to those obtained by the F-D method, but in a much shorter time, i.e., with lower energy and using a simple method.

Chromatographic characterization of juice in fruits of different Japanese quince (Chaenomeles japonica L.) genotypes cultivated in Sweden

The juice in fruits of 19 genotypes of Japanese quince (Chaenomeles japonica), representing plant breeding material, was characterised using high performance liquid chromatography. The juice was extracted by halving and squeezing the fruit. Samples of Japanese quince juice were always analysed fresh. The main compounds found were sugars: glucose (131-1056 mg 100 ml-1), fructose (351-2515 mg 100 ml-1) and sorbitol (10-367 mg 100 ml-1); organic acids: malic acid (2.27-4.84 g 100 ml-1) and quinic acid (0.50-2.50 g 100 ml-1); amino acids: aspartic acid (0.8-10.7 mg 100 ml-1), asparagine (0.2-36.3 mg 100 ml-1) and glutamic acid (6.2-17.7 mg 100 ml-1); the cation potassium (145-214 mg 100 ml-1) and the anion fluoride (21-122 mg 100 ml-1). These results on composition suggest that Japanese quince may be an interesting raw material source of valuable substances and its juice an ingredient for the food industry. A principal components analysis separated the Japanese quince genotypes, thus indicating a clear difference in the chemical composition of the juice.

Japanese Quince (Chaenomeles japonica) as a Potential Source of Phenols: Optimization of the Extraction Parameters and Assessment of Antiradical and Antimicrobial Activities

The value of fruits is determined by the quantity and variety of biologically active compounds they contain, and their benefits on human health. This work presents the first study of the biochemical composition and antibacterial activity of the new Japanese quince (JQ) cultivars ‘Darius’, ‘Rondo’, and ‘Rasa’ fruits. The total phenolic content (TPC) was determined using the Folin–Ciocalteu method and each compound was identified by HPLC High Performance Liquid Chromatography. The antimicrobial activity against three Gram-positive and three Gram-negative bacteria, and one yeast strain, was evaluated by the agar well diffusion method using three different concentrations. The free radical scavenging activity was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) methods and ranged from 99.1 to 115.9 μmolTE/100 g, and from 372 to 682 μmolTE/100 g, respectively. TPC ranged from 3906 to 4550 mgGAE/100 g, and five compounds, isoquercitrin, rutin, (+)-catechin, (–)-epicatechin, and chlorogenic acid were identified. All JQ extracts possessed antimicrobial activity against Gram-positive and Gram-negative bacteria, and Enterococcus faecalis (ATCC 29212) was the most sensitive strain. These results indicate that JQ fruits are a significant source of bio-compounds, which can enrich the diet with strong antioxidants, and they are very promising as a substitute for chemical preservatives in the food and cosmetic industry.