The objective of our research was to evaluate the possible alteration of the organoleptic properties of eggs produced by hens (Lohmann Brown-Classic) fed with diets containing different doses of an industrial by-product enriched with organic zinc (Zincoppyeast, ZP): Control 0%, ZP 2.5%, and ZP 5.0%. Eggs were collected after 30 days (batch 1) and 60 days (batch 2) of feeding with the experimental diets and subjected to chemical, microbiological, human sensory, e-nose, and e-tongue analyses. There was no significant difference among the microbiological status of eggs of the three groups, but there were significant differences (p < 0.05) in the fat (9.5% vs. 9.3%) and protein contents (12.7% vs. 13.4%) of the Control and ZP 5.0% groups, respectively. Human sensory analysis showed no clear change in the organoleptic characteristics of the eggs. Using linear discriminant analysis (LDA), the e-tongue could recognize the three groups of eggs in batch 1 and batch 2 with 95.9% and 100% accuracy and had a prediction accuracy of 64.8% and 56.2%, respectively. When the eggs were incubating at 50 °C or 80 °C before the e-nose analysis, the groups of eggs could be recognized with 98.0% and 82.7% accuracy, and predicted with 68.5% and 62.2% accuracy, respectively, using principal component analysis-based discriminant analysis (PCA–DA). The aroma compounds and respective sensory descriptors showing changes among the different groups of eggs (batch, storage, and feeding) were identified based on the e-nose analysis. The supplementation of laying hens’ feed with the investigated industrial by-product can be applied without any substantial effect on egg quality, which can, however, be detected with advanced analytical methods.
15 September 2015 in Agriculture and Agricultural Science Procedia
The objective of this study was to evaluate the quantity of some phenolic compounds and free radical scavenging activity of strawberries (Fragaria x ananassa Duch.) during storage period at different temperatures. Freshly harvested of three strawberry cultivars fruits (‘San Andreas’, ‘Benicia’ and ‘Albion’) were placed in polyethylene bags and kept in refrigerated (4 °C) and frozen (-85 °C) conditions for 7 days. Therefore, the analyses performed were applied on the fruits in stages: fresh, refrigerated and frozen. With regard to the bio compounds analysis, we mention: total phenolic content (TPC) expressed as g gallic acid equivalents (GAE), total flavonoid content (TFC) expressed as g of rutin equivalents (RE), and free radical scavenging activity expressed as 50% effective concentration (EC50) (mg/ml). With regard to the TPC in all analyzed storage stages have revealed ‘San Andreas’ cultivar with a maximum content of 0.326 g GAE / 100 g fresh weight (FW). Also, the same cultivar recorded high levels of total flavonoid content of 0.424 g RE / 100 g FW, all at the end of refrigeration period. In terms of free radical scavenging activity, ‘Benicia’ cultivar highlighted the best results EC50 = 3.094 mg/ml.
This study presents the behavior of the identified yeast strain S. cerevisiae, isolated from Busuioacă de Bohotin grapes from the Pietroasa winery, during the process of fermentation to obtain dry active yeast biomass for the winemaking process. In this respect, we promoted an optimization strategy for obtaining active dry yeast biomass. The cultivation conditions for micropilot fermentation (temperature, pH, carbon source, and nitrogen source) were selected and designed according to a Taguchi design with four factors and three levels. Reproducibility testing was conducted under specific fermentation parameters: temperature (32 °C), pH (4.5), carbon source (12%), and nitrogen source (0.7%). Following the optimization process, two combinations of cultivation parameters were selected, and one of them, based on the results, was selected for further analysis. Quantitative data were obtained, showing dry yeast biomass (DCW) at 1.39 g/100 mL and protein content at 45.57%. The active yeast was then used in the winemaking process for Tămâioasă Românească and Busuioacă de Bohotin varieties at Pietroasa winery for validation. This optimization aims to facilitate easy and rapid production of fresh wine yeast tailored to the local winemaking practices of Pietroasa winery, with real application potential in other viticultural areas, aligning with the terroir concept.