Physicochemical characterization of blueberry (Vaccinium spp.) juices from 55 cultivars grown in Northern Spain

Blueberry (Vaccinium spp.) cultivation has experienced a notable increase both for its good organoleptic characteristics and the nutritional and functional properties of this berry. The aim of this study was the physicochemical characterization of blueberry juices obtained from 55 blueberry cultivars grown under the same environmental conditions for 2–4 years. The results provide a broad and robust database, both for the number of cultivars and the periods of monitoring thereof, in order to cover different aspects of blueberry processing, and more specifically, production of juices. Blueberries belonging to V. virgatum cultivars showed the higher values of total anthocyanin content, total phenolic content, antioxidant activity, soluble solids, and pH, and V. corymbosum cultivars the higher level of titratable acidity. Results also showed a high variability among cultivars. Observed variations can be used in plant breeding and classification of blueberry cultivars, at least, at the species level

Application of central composite design in the fermentation of apple pomace to optimize its nutritional and functional properties

Simultaneous optimization of protein, soluble and insoluble dietary fibre, total phenolic content, and antioxidant activity was carried out in apple pomace by using response surface methodology (RSM) and solid state fermentation. A central composite design (CCD) was used to optimize the content of nutritional and functional properties, and two factors were studied: time and temperature of fermentation. The fermentation of apple pomace under the best conditions (29.5 ºC and 4.9 days) allowed the depletion of fermentable sugars, an increase the contents of protein and insoluble dietary fibre (36% and 23%, respectively), while soluble dietary fibre, total phenolic content, and antioxidant activity remained constant

Distribution of the principal minor volatiles during cider distillation in ‘alquitara’

A study of minor volatiles from 12 fractions collected during distillation of cider in ‘alquitara’ was carried out. Compounds favouring spirit quality are found in the first half of the distillate. Some compounds imparting aromatic defects could be eliminated by removing a percentage of heads during distillation. In contrast, when distilling ciders without defects, removing heads would not be justified, as their incorporation in the final distillate should lead to obtaining spirits with higher aromatic riches. Tails, however, which are mainly constituted by unpleasant aromas, must be rigorously removed to avoid incorporating compounds that could reduce the quality of the final product