Assessment of colour changes during storage of elderberry juice concentrate solutions using the optimization method

BACKGROUND

Elderberries are a source of dietary supplements and bioactive compounds, such as anthocyanins. These dyes are used in food technology. The aim of the study was to assess the changes in colour parameters, anthocyanin contents and sensory attributes in solutions of elderberry juice concentrates during storage in a model system and to determine predictability of sensory attributes of colour in solutions based on regression equations using the response surface methodology.

METHODS

The experiment was carried out according to the 3-level factorial design for three factors. Independent variables included pH, storage time and temperature. Dependent variables were assumed to be the components and colour parameters in the CIE L*a*b* system, pigment contents and sensory attributes.

RESULTS

Changes in colour components X, Y, Z and colour parameters L*, a*, b*, C* and h* were most dependent on pH values. Colour lightness L* and tone h* increased with an increase in experimental factors, while the share of the red colour a* and colour saturation C* decreased. The greatest effect on the anthocyanin concentration was recorded for storage time. Sensory attributes deteriorated during storage. The highest correlation coefficients were found between the value of colour tone h* and anthocyanin contents in relation to the assessment of the naturalness and desirability of colour. A high goodness-of-fit of the model to data and high values of R2 for regression equations were obtained for all responses.

CONCLUSIONS

The response surface method facilitates optimization of experimental factor values in order to obtain a specific attribute of the product, but not in all cases of the experiment. Within the tested range of factors, it is possible to predict changes in anthocyanin content and the sensory attributes of elderberry juice concentrate solutions as food dye, on the basis of the lack of a fit test. The highest stability of dyes and colour of elderberry solutions was found in the samples at pH 3.0, which confirms the advisability of using an anthocyanin preparation to shape the colour of high-acidity food products, such as fruit fillings, beverages,desserts.

Purple carrot anthocyanins suppress lipopolysaccharide-induced inflammation in the co-culture of intestinal Caco-2 and macrophage RAW264.7 cells

This study was designed to evaluate the anti-inflammatory effects of purple carrot anthocyanins (PCA) with respect to gut inflammation, simulated in a co-culture system consisting of intestinal epithelial Caco-2 cells and RAW264.7 macrophages. The obtained results indicated that PCA extract down-regulates the mRNA expression of proinflammatory interleukins Il-1β (↓91%) and Il-6 (↓69%) as well as inflammatory mediators, such as cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNos), in lipopolysaccharide-activated RAW264.7 cells. The decrease in the generation of prostaglandin E2 (↓48%) and nitric oxide (↓26%) was observed as a result of the inhibition of Cox-2 (↓25%) and iNos (↓12%) mRNA expressions, respectively. Moreover, the PCA reduced mRNA expression (↓40%) and production (↓17%) of IL-8 in intestinal cells. The anti-inflammatory effect of PCA was contributed to the protection of the intestinal barrier, which was disrupted upon the stimulation of macrophages. These findings may provide preliminary justification for the use of PCA in further studies focused on the prevention and therapy supporting the conventional treatment of inflammatory bowel diseases.

The effect of pre-treatment and modified atmosphere packaging on contents of phenolic compounds and sensory and microbiological quality of shredded celeriac

BACKGROUND

The aim of this study was to determine the effect of washing (4 °C, 120 s) or soaking (4 °C, 600 s) of shredded celeriac in tap water on changes in contents of phenolic compounds, including furanocoumarins, and sensory and microbiological quality during 12 days of storage. The product was packaged in air or modified atmosphere containing 2/10/88 kPa O2/CO2/N2.

RESULTS

The applied pre-treatment consisting of washing or soaking of shredded celeriac in water resulted in decreases in 8-methoxypsoralen content by approximately 50 and 70% respectively and phenolic content by 30% compared with samples that were not subjected to pre-treatment. During storage of shredded celeriac, a further significant (P ≤ 0.05) reduction in phenolic compounds and an approximately 2.5-fold increase in the total content of furanocoumarins were found. The application of modified atmosphere packaging had a significant effect on the maintenance of good sensory and microbiological quality of the tested product.

CONCLUSION

Modified atmosphere packaging of shredded celeriac not subjected to pre-treatment made it possible to obtain a product with good sensory and microbiological quality and the highest content of phenolic compounds. The level of furanocoumarins recorded in the tested product does not constitute a health hazard.

Feasibility of ablating normal renal parenchyma by interstitial photon radiation energy: study in a canine model

BACKGROUND AND PURPOSE

A miniature photon radiosurgery system (PRS) has been described as an alternative to surgical resection and external-beam radiation for tumors and may now offer an alternative for ablation of renal lesions. We evaluated the feasibility of ablation by PRS in a normal parenchyma canine model.

MATERIALS AND METHODS

Twelve mongrel dogs were used in this survival study. In the left and right kidneys of each animal, a peripheral lesion and central-hilar lesion, respectively, were induced with PRS. The probes were placed in the renal parenchyma, and local radiation of 15 Gy at a radius of 1.3 cm was delivered over 10 minutes. Serum electrolytes were measured serially. Computed tomography scans were obtained, and the animals were sacrificed for pathologic correlation. In a separate study, the liver received three additional treatments of 10 to 20 minutes of radiation.

RESULTS

Eleven dogs survived this 6-month study and were sacrificed as scheduled. One animal expired after 2 weeks from radiation-induced fulminant hepatic failure with normal renal function. No other complications were observed. The average lesion size was 2.5 cm in diameter. Histologic analysis confirmed coagulative necrosis with sharp demarcation from the surrounding parenchyma.

CONCLUSION

Preliminary studies demonstrate the feasibility of PRS ablation of the renal parenchyma. Further tumor model testing will be important to determine the ultimate efficacy of local photon radiation energy.

The study of heptenophos and triazophos residues in vegetables treated with the organophosphorus insecticides Hostaquick and Hostathion

The residues of heptenophos and triazophos (active components of Hostaquick and Hostathion) were determined in several vegetable crops during the growing period. Heptenophos residues decreased below the limit of detection (0.001 mg/kg) in most of the crops one week after the treatment. However, the decline of triazophos in vegetables below the limit of detection (0.002 mg/kg) depended on the method of crop treatment.

Residues of cycloate and influence of herbicides on some of nutritional factors in spinach

The influence of cycloate (active component of Ro-Neet 6E) on the biological value and residues in spinach was studied. During the growing season of spinach, cycloate residues decreased rapidly until by harvest time levels 0.0005--0.0008 mg/kg. had been reached. None of the studied herbicides had negative influence on the chemical composition of spinach.