Iwona Ścibisz

Fatty acids and sterols composition, and antioxidant activity of oils extracted from plant seeds.

This study determined and compared the contents of bioactive components in plant seed oils extracted with n-hexane (Soxhlet method) and chloroform/methanol (Folch method) from coriander, caraway, anise, nutmeg and white mustard seeds. Oleic acid dominated among unsaturated fatty acids in nutmeg and anise seed oils while petroselinic acid was present in coriander and caraway oils. Concerning sterols, β-sitosterol was the main component in seed oils extracted with both methods. The content of total phenolics in nutmeg, white mustard and coriander seed oils extracted with chloroform/methanol was higher than in their counterparts prepared with n-hexane. The seed oil samples extracted according to the Folch method exhibited a higher ability to scavenge DPPH radicals compared to the oil samples prepared with the Soxhlet method. DPPH values of the methanolic extracts derived from oils produced with the Folch method were also higher than in the oils extracted with n-hexane.

The effect of microwave pretreatment of seeds on the stability and degradation kinetics of phenolic compounds in rapeseed oil during long-term storage.

Storage stability and degradation kinetics of phenolic compounds in rapeseed oil pressed from microwave treated seeds (0, 2, 4, 6, 8, 10min, 800W) during long-term storage (12months) at a temperature of 20°C was discussed in the current study. The dominant phenolic compound detected in rapeseed oil was canolol, followed by minor amounts of free phenolic acids and sinapine. The most pronounced effect of seeds microwaving was noted for canolol formation - after 10-min exposure the quantity of this compound was approximately 63-fold higher than in control oil. The degradation of phenolics during storage displayed pseudo first-order kinetics. Differences in the initial degradation rate (r0) demonstrated significant impact of the period of seeds microwave exposure on the degradation rates of phenolic compounds. Results of the half-life calculation (t1/2) showed that the storage stability of phenolic compounds was higher in oils produced from microwave treated rapeseeds than in control oil.

UPLC-PDA-Q/TOF-MS Profile of Polyphenolic Compounds of Liqueurs from Rose Petals (Rosa rugosa)

Polyphenolic compounds, as a secondary metabolite of plants, possess great nutritional and pharmacological potential. Herein, we applied the green analytical method to study the nutrient profile of Rosa rugosa petals and liqueurs manufactured from them. Using the fast and validated ultra performance liquid chromatography-photodiode detector-quadrupole/time of flight-mass spectrometry (UPLC-PDA-Q/TOF-MS) method, we confirm the presence of the following compounds: phenolic acids, flavonols, flavan-3-ols and hydrolisable tannins (gallotannins and ellagitannins). R. rugosa petals contains up to 2175.43 mg polyphenols per 100 g fresh weight, therein 1517.01 mg ellagitannins per 100 g fresh weight. Liqueurs, traditionally manufactured from said petals using a conventional extraction method (maceration), also contain polyphenols in significant amounts (from 72% to 96% corresponding to percentage of theoretical polyphenol content in the used petals), therein ellagitannins amount to 69.7% on average. We confirmed that traditional maceration, most common for the isolation of polyphenols, is still suitable for the food industry due to its using aqueous ethanol, a common bio-solvent, easily available in high purity and completely biodegradable. Therefore R. rugosa used as a food may be considered as an ellagitannin-rich plant of economic importance. Manufactured rose liqueurs were stable and kept all their properties during the whole period of aging.

Antioxidant properties and effect on lactic acid bacterial growth of spice extracts

The total phenolic content (TPC) and antioxidant capacity as determined by 2,2-diphenyl-1-picrylhydrazyl, 2,2ʹ-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid and ferric reducing antioxidant power assays of spice extracts such as rosemary, lemon balm, hyssop, nettle and cumin seeds were investigated. The effect of spice extracts on the growth of selected lactic acid bacteria (LAB) was also analysed. Lemon balm extract exhibited the highest TPC and antioxidant capacity while the nettle and cumin seeds extracts were characterized by the lowest values. Spice extracts had no impact on the growth of the most tested LAB except for rosemary extract, which showed an inhibitory effect towards all strains of Lactobacillus acidophilus and L. delbrueckii. These results suggest that spice extracts may be considered as additives in dairy and meat products in which LAB are present.

Effect of Pullulan Coating on Postharvest Quality and Shelf-Life of Highbush Blueberry (Vaccinium corymbosum L.)

Fruits form an important part of a healthy human diet as they contain many ingredients with proven pro-health effects such as vitamins, phenolic compounds, organic acids, fiber, and minerals. The purpose of this work was to evaluate the effect of pullulan coating on the quality and shelf life of highbush blueberry during storage. General appearance, weight loss, dry matter, soluble solid content, reducing sugars, content of L-ascorbic acid, phenolic compounds (total phenolics, phenolics acids and anthocyanins) were determined in uncoated and coated blueberries fruits. The microbiological efficiency of pullulan coating was also evaluated. All parameters were monitored during storage at 4 °C and 16 °C by 28 and 14 days, respectively. The study showed that pullulan coating protects perishable food products especially susceptible to mechanical injury including fruits such as blueberries. Pullulan acts as a barrier that minimizes respiration rate, delaying deterioration and controlling microbial growth.

Profile of the Phenolic Compounds of Rosa rugosa Petals

Rosa rugosa petals are a rich source of phenolic compounds, which determined their antioxidant properties. The aim of this study was to determine the polyphenolic composition of not processed petals of Rosa rugosa collected from the commodity crops and to determine the variability of the contained therein polyphenols between harvesting seasons. Twenty polyphenols were identified by UPLC-ESI-MS. The main fraction of polyphenols was ellagitannins, which are 69 to 74% of the total polyphenols of the petals. In the petals of Rosa rugosa, four anthocyanins have been identified: cyanidin 3,5-di-O-glucoside, peonidin 3-O-sophoroside, peonidin 3,5-di-O-glucoside, and peonidin 3-O-glucoside, of which the predominant peonidin 3,5-di-O-glucoside represented approx. 85% of all the determined anthocyanin compounds. It was found that the petals of Rosa rugosa are a valuable source of bioactive compounds and can be considered as a healthy valuable resource.

Mechanical hulling and thermal pre-treatment effects on rapeseed oil antioxidant capacity and related lipophilic and hydrophilic bioactive compounds

Abstract In this study, the effect of rapeseed mechanical hulling and thermal pre-treatment by microwaves (from 2 to 10 min with 2-min intervals, 800 W) and roasting (from 20 to 100 min with 20-min intervals, 165 °C) on the content of phytochemicals in the oil was investigated. Results showed that both pre-treatments applied differentiated the oils in terms of the content of bioactive compounds. In general, oils pressed from hulled and thermally pre-treated seeds contained higher content of tocopherols, PC-8 and phytosterols, while oils pressed from non-hulled and pre-processed seeds had significantly higher concentration of polyphenols. Both microwaving and roasting contributed to an increase of antioxidant capacity of studied oils. The increase of radical scavenging activity of oils was seen mainly in hydrophilic fraction of oil, which was highly positively correlated with the amount of canolol formed during seeds heating.

Propionibacterium spp.-source of propionic acid, vitamin B12, and other metabolites important for the industry

Bacteria from the Propionibacterium genus consists of two principal groups: cutaneous and classical. Cutaneous Propionibacterium are considered primary pathogens to humans, whereas classical Propionibacterium are widely used in the food and pharmaceutical industries. Bacteria from the Propionibacterium genus are capable of synthesizing numerous valuable compounds with a wide industrial usage. Biomass of the bacteria from the Propionibacterium genus constitutes sources of vitamins from the B group, including B12, trehalose, and numerous bacteriocins. These bacteria are also capable of synthesizing organic acids such as propionic acid and acetic acid. Because of GRAS status and their health-promoting characteristics, bacteria from the Propionibacterium genus and their metabolites (propionic acid, vitamin B12, and trehalose) are commonly used in the cosmetic, pharmaceutical, food, and other industries. They are also used as additives in fodders for livestock. In this review, we present the major species of Propionibacterium and their properties and provide an overview of their functions and applications. This review also presents current literature concerned with the possibilities of using Propionibacterium spp. to obtain valuable metabolites. It also presents the biosynthetic pathways as well as the impact of the genetic and environmental factors on the efficiency of their production.

Acid contents and the effect of fermentation condition of Kombucha tea beverages on physicochemical, microbiological and sensory properties

ABSTRACT Kombucha is a healthy beverage which is a final result of tea fermentation by adding a starter culture of the acetic acid bacteria and yeasts. The effect of fermentation conditions on physicochemical, microbiological and sensory properties of Kombucha tea beverages was evaluated with emphasis placed on determining sugars and organic acids content, including pro-health glucuronic acid. Fermentation process was conducted for 10 days at 20°C, 25°C and 30°C. The optimal conditions for the fermentation of Kombucha tea beverages were a temperature of 25°C and a period of 10 days which allowed to retrieve a product with good physicochemical, microbiological and sensory quality. The content of glucuronic acid increased during fermentation at all temperatures reaching the highest, on the 10th day of fermentation at 25°C. It was observed that all beverages were a good overall quality, whereas Kombucha fermented at 25°C was assessed as the highest.