Interactions between fecal bacteria,bile acids and components of tomato pomace

Food Science and Biotechnology - The tomato pomace obtained during processing as a residue of tomato processing from large industry. The interactions between tomato pomace and fecal bacteria, bile...     

Perceptions of the health and convenience characteristics of fresh and dried fruits

Dried fruits consumption has not received much research attention, although these foods are associated with potential health benefits. Therefore, the aim of this study was to compare fresh fruits and dried fruits on measures of health, convenience and consumer feelings.An on-line questionnaire that measured consumers' perceptions of the health benefits and convenience characteristics and their feelings about the consumption of both fresh fruits (apples and plums) and dried fruits (e.g., raisins, dates, and apricots) was completed by 693 respondents (Polish, French, and Dutch).Generally, fresh fruits were perceived to be healthier and less convenient than dried fruits. Consumers also reported more positive feelings about the consumption of fresh fruits compared to dried fruits. The more that the respondents were willing to sacrifice for their health, the more positively they rated the health aspects of both fresh and dried fruits, as well as several perceptions of convenience of both fresh and dried fruits. Health preoccupation was unrelated to most of the convenience perceptions and was associated with lower scores on several perceptions of healthiness. Recommendations for the consumer-oriented development of dried fruits are also provided.     

Application of various methods for determination of the color of cocoa beans roasted under variable process parameters

Cocoa beans of Forastero variety from Togo were subjected to roasting under either constant or variable process parameters. The variable process parameters were roasting air flow rate, temperature and relative humidity. The color of roasted cocoa beans was determined by pigment extraction under various conditions followed by either their spectrophotometric assays or CIE L*a*b measurements. Also the Maillard compounds index and total polyphenols content correlated with progress of the browning of beans were determined. It was found that an increase in the roasting air relative humidity stimulated formation of brown pigments, while elevated temperature caused worsening of color parameters of roasted cocoa beans. The most suitable method of color characterization of roasted cocoa beans was found to be pigments extraction combined with either separation of their fractions or CIE L*a*b measurements. These assays revealed that cocoa beans roasted under variable roasting air flow rate were characterized by improved color parameters. The relatively simple and inexpensive CIE L*a*b measurements ensured fast analysis of color parameters, while total polyphenols in roasted cocoa beans were quickly estimated by using F–C reagent. Furthermore, quantification of melanoid pigments in roasted cocoa beans can be based on determination of the index of nonenzymatic browning products content, which is relatively simple and inexpensive.     

Influence of Pulsed Electric Field Protocols on the Reversible Permeabilization of Rucola Leaves

Reversible electropermeabilization of plant tissues with heterogeneous structure represents a technological challenge as the response of the different structures within the same specimen to the application of electric field may differ due to different cell sizes, extracellular space configurations, and electrical properties. The influence of five different pulsed electric field protocols with different pulse polarity, number of pulses (25, 50, 75, 100, 250, and 500), and intervals between pulses (no intervals and 1- and 2-ms intervals) on the reversible permeabilization of rucola (Eruca sativa) leaves was investigated. The electric field intensity was 600 V/cm. Electrical resistance of the bulk tissue was measured before and after electroporation, and propidium iodide was used to analyze the electroporation at the surface of the leaf. Leaf viability was assessed from survival in storage, and cell viability was investigated with fluorescein diacetate. Results indicate that the viability of the leaves could not be predicted by measurements of electrical resistance or permeabilization levels of the leaf surface. Higher survival rate was demonstrated when applying bipolar pulses compared with monopolar pulses, but the latter proved to be more effective than bipolar pulses for permeabilizing the surface of the leaves. Longer intervals between bipolar pulses resulted in increased viability preservation, while the number of electroporated cells on the leaf surface was comparable for all tested protocols.     

Optimization of Selenium-Enriched Mycelium of Lentinula edodes (Berk.) Pegler as a Food Supplement

Our goal was to optimize the growth conditions of submerged mycelial cultures of Lentinula edodes (Shiitake mushroom) in order to obtain a new dietary supplement enriched in selenium We designed a process technology in which mycelial cultures were cultivated in media composed of beet molasses, 10%; liquid stillage, 5%; corn steep liquor, 0.15%; and KH₂PO₄, 0.3%, enriched with selenium in concentrations ranging from 0 to 100 μg/mL by the addition of sodium selenite of selenic acid. Se concentrations in mycelial dry mass rose from 0.001 mg/g (mycelia cultivated in media containing no selenium) to 50 mg/g (mycelia cultivated in medium containing 100 μg Se/mL). The highest mycelial specific growth rate (0.46/day) was recorded when the concentration of selenium in the medium was lower than 20 μg/mL. In vitro, estimated Se bioavailabilities from selenized mycelium strongly depended on its preparation in a proper manner and were 60% and 82% for dried mycelium and mycelial lyophilizate, respectively. Our results suggest that these optimized culture conditions could be applied to obtain a new Se-enriched dietary supplement.     

Biological Availability and Preliminary Selenium Speciation in Selenium-Enriched Mycelium of Lentinula edodes (Berk.)

Our goal is to obtain a new food supplement — a chemopreventive preparation derived from selenium (Se)-enriched Lentinula edodes mycelium. In the present study the bioavailability of selenium from Se-enriched mycelium preparations was tested in vitro and in vivo. Three different preparations of selenated mycelium were compared: dried mycelium, lyophilized mycelium, and lyophilized-autolyzed mycelium. In vitro, estimated Se bioavailabilities were 60%, 82%, and 98%, respectively. In vivo bioavailability was determined in rats. As reference, sodium selenite and Se yeast formulations were used at an Se-equivalent dose. The pharmacokinetic data for tested mycelial preparations suggest a rapid but incomplete Se absorption, and rapid elimination, without risk of accumulation. The speciation of selenium in Se-enriched mycelial cultures was carried out by specific oxido-reduction reactions. For tested mycelium the main part of Se was in the 0 and IV oxidation states in inorganic form or combined in a lipid or carbohydrate structure, about 47% was in the –II state in Se-amino acids or in other undefined water- or alcohol soluble organic compounds. Differences in pharmacokinetic data for Se yeast and L. edodes mycelial formulations probably arise from differences in Se speciation. Our data suggest that formulations of selenized Lentinula edodes mycelium could be used in chemoprevention as food supplements.     

Biodegradability evaluation of wastewaters from malt and beer production

This study reports results of respirometric measurements of activated sludge biodegrading the substrate in wastewater originating from the following brewery plant production departments: malt house, brewhouse, fermentation house and racking house. The process was conducted at two temperatures: 10 and 20°C with activated sludge adapted to brewery wastewaters. The loading of activated sludge reached 0.25 g chemical oxygen demand per gram dry matter per day, which assured complete degradation of organic matter. The physicochemical characteristics of the wastewaters are provided. The study demonstrates a correlation between the site of wastewater generation, the specific character of a unitary technological process and the quality of the wastewater discharged to the sewage system, including biodegradability. Despite significant differences in the quality of the wastewaters, they were characterized by high biodegradability at a temperature of 10 and 20°C and by the C:N:P ratio being beneficial for biological treatment, irrespective of their source of origin. Copyright © 2013 The Institute of Brewing & Distilling     

Mercury in fruiting bodies of dark honey fungus (Armillaria solidipes) and beneath substratum soils collected from spatially distant areas

BACKGROUND: This paper reports data on bioconcentration potential and baseline mercury concentrations of fruiting bodies of dark honey fungus (Armillaria solidipes) Peck and soil substrate layer (0–10 cm) from 12 spatially distant sites across Poland. Mercury content of caps, stipes and soil samples were determined using validated analytical procedure including cold‐vapor atomic absorption spectroscopy after thermal decomposition of the sample matrix and further amalgamation and desorption of mercury from gold wool. RESULTS: Mean mercury concentrations ranged from 20 ± 8 to 300 ± 70 ng g^?1 dry weight (dw) in caps, from 20 ± 6 to 160 ± 40 ng g^?1 dw in stipes, and in underlying soil were from 20 ± 2 to 100 ± 130 ng g^?1 dw. The results showed that stipes mercury concentrations were 1.1‐ to 1.7‐fold lower than those of caps. All caps and the majority of stipes were characterized by bioconcentration factor values > 1, indicating that dark honey fungus can be characterized as a moderate mercury accumulator. CONCLUSION: Occasional or relatively frequent eating of meals including caps of dark honey fungus is considered safe in view of the low total mercury content, and the mercury intake rates are below the current reference dose and provisionally tolerable weekly intake limits for this hazardous metal. © 2012 Society of Chemical Industry     

The Usefulness of Intermediate Products of Plum Processing for Alcoholic Fermentation and Chemical Composition of the Obtained Distillates

In this study, an evaluation of intermediate products of plum processing as potential raw materials for distillates production was performed. Effects of composition of mashes on ethanol yield, chemical composition and taste, and flavor of the obtained spirits were determined. The obtained results showed that spontaneous fermentations of the tested products of plum processing with native microflora of raisins resulted in lower ethanol yields, compared to the ones fermented with wine yeast Saccharomyces bayanus. The supplementation of mashes with 120 g/L of sucrose caused an increase in ethanol contents from 6.2 ± 0.2 ÷ 6.5 ± 0.2% v/v in reference mashes (without sucrose addition, fermented with S. bayanus) to ca. 10.3 ± 0.3% v/v, where its highest yields amounted to 94.7 ± 2.9 ÷ 95.6 ± 2.9% of theoretical capacity, without negative changes in raw material originality of distillates. The concentrations of volatile compounds in the obtained distillates exceeding 2000 mg/L alcohol 100% v/v and low content of methanol and hydrocyanic acid, as well as their good taste and aroma make the examined products of plum processing be very attractive raw materials for the plum distillates production.     

Antimicrobial Activity of a Pullulan–Caraway Essential Oil Coating on Reduction of Food Microorganisms and Quality in Fresh Baby Carrot

This research evaluated the antimicrobial efficacy of pullulan films containing caraway essential oil (CEO). The films were prepared from a 10% of pullulan, containing from 0.12% to 10.0% of CEO. The composition of the CEO was analyzed with the use of gas chromatography. The antimicrobial activity of the CEO was evaluated with the method of serial microdilutions, and the films containing CEO—with the agar diffusion method against selected Gram‐negative, Gram‐positive bacteria, and fungi. The structure of the film surface and its cross‐section were analyzed using a scanning electron microscope (SEM). Analyses were also carried out to determine the efficacy of a pullulan coating with 10% CEO on baby carrots experimentally inoculated with Salmonella enteritidis, Staphylococcus aureus, Saccharomyces cerevisiae, or Aspergillus niger and stored at a room temperature for 7 d. At a concentration of 0.12%, CEO inhibited the growth of all the tested microorganisms. Pullulan films containing 8% to 10% of CEO were active against all tested microorganisms. Populations of S. aureus on carrot samples were reduced by approximately 3 log CFU/g, while those of A. niger and S. cerevisiae by, respectively, 5 and 4 log CFU/g, after 7 d of storage. S. enteritidis was the most resistant among the tested species, since it was not significantly reduced after 7 d of storage. At the end of storage, samples treated with pullulan–caraway oil coating maintained better visual acceptability than control samples. Results of this study suggest the feasibility of applying a pullulan film with incorporated CEO to extend the microbiological stability of minimally processed foods.