Color stability of fruit yogurt during storage.

This article describes the evaluation of the anthocyanins stability in yogurts with strawberry, sour cherry, and blueberry fruit preparation during 8-week storage period under refrigerated condition. The differences in anthocyanin degradation rate and color changes between stirred yogurts and fruit-on-the-bottom yogurts (fruit preparation was on-the-bottom of package) were compared. Anthocyanin content in fruit yogurts showed a significant decreased during the storage, especially for the first 2 weeks. There were differences in the rate of pigment degradation between yogurt obtained from a different species of fruit. The half-life of the pigments in stirred yogurt with the preparation of strawberry, sour cherry, and blueberry was found to be 5.5, 6.7, and 19.0 weeks, respectively. The addition of fruit preparation on the bottom of yogurt could be used to reduce the pigment degradation during storage. The half-life of anthocyanin in fruit-on-the-bottom yogurts was 39-63% higher than in the blending samples. A significant alteration in the pigment profile during storage of blueberry yoghurt was observed. The proportion of malvidin-glucosides and acylated anthocyanins increased with time of storage, with a concomitant decrease in proportion of petunidin, delphinidin and peonidin derivatives.

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.

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.

High pressure processing and thermal pasteurization of strawberry purée: quality parameters and shelf life evaluation during cold storage.

This study was aimed at monitoring changes in the quality of strawberry purée preserved by high pressure processing (HPP) and thermal pasteurization (TP) during cold storage (6 °C) and determining its optimal storage period. The storage period of strawberry purée treated at 500 MPa, 50 °C, 15 min based on microbiological changes was 12 weeks. During this period, purée lost 32% of polyphenols, 73% of anthocyanins and entire vitamin C. Color changes described as dE increased up to 5.05 whereas the overall sensory quality decreased by 3 points on a 9-point scale. Under similar storage conditions, TP-preserved purée lost only 28% of polyphenols and 54% of anthocyanins, and entire vitamin C. Color changes were more visible (dE = 7.21) compared to the HPP sample whereas the overall sensory quality decreased only by 2 points. Recommended cold shelf-life for the HPP product was estimated at 6 weeks, during which period HPP-preserved purée had higher content of polyphenols and colour parameters compared to TP purée.

Estimated dietary intakes of nitrates in vegetarians compared to a traditional diet in Poland and acceptable daily intakes: is there a risk?

BACKGROUND: Vegetarian diets, by definition, are rich in vegetables and so may have high levels of nitrates, that can elicit both positive or negative effects on the human body. Exposure to nitrates can thus be potentially higher for this population group. OBJECTIVE: To estimate dietary nitrates intakes in Polish vegetarians and compare these with the Polish average. MATERIAL AND METHODS: A sample of 86 vegetarians were surveyed via a questionnaire to determine nitrate intake for those adopting a vegetarian diet. Nitrate intakes for the average Pole were obtained from the Central Statistical Office. RESULTS: The domestic intake of nitrate, per average person, during 2000-2009, ranged from 115.5 to 133.7 mg NaNO3 with a mean of 125 mg NaNO3 of which 35.4% constituted the Acceptable Daily Intake (ADI). For vegetarians, the corresponding levels ranged from 37.3 to 2054.3 mg NaNO3 with a mean intake of 340.1 mg NaNO3 of which 95.8% represented the ADI. This was almost twice more than values obtained from calculating nitrate intakes of a typical 7-day vegetarian menu; 104.5 to 277.6 mg NaNO3, with a mean 175.9 mg NaNO3 with the 49.1% making up the ADI. CONCLUSIONS: The nitrate intakes in the tested vegetarians were 140 to 270% higher than ones for the average Pole, however in both cases the ADI was not exceeded. Nevertheless, the higher intake of nitrates so observed in vegetarians can be hazardous to some from this population group.

Stabilization of anthocyanin and skullcap flavone complexes--investigations with computer simulation and experimental methods.

We examined the stabilization of anthocyanins with flavones from the practical and theoretical perspective. The influence of addition of skullcap flavones, heating to 50 °C, and 12 day storage time (in the presence and absence of light) on the stability of anthocyanins in honeysuckle concentrates was investigated experimentally. Theoretical study was conducted with molecular dynamics methods in a model system, preceded by simulated annealing and thermalization. By the methods of the computer simulation of the copigmentation process we determined the sites responsible for the stabilization of a cyanidin quinoidal base-baicalin complex. We revealed both direct and water-mediated hydrogen bondings that keep the lamellar stacking structure of these molecules in the bounded form in water medium. The stacking occurs also due to hydrophobic interactions of the rings of both molecules. The experimental part of the study confirmed the effectiveness of anthocyanins stabilization in a concentrate of honeysuckle with the use of skullcap flavones.