Roberto Romaniello

Prevention of enzymatic browning in sliced potatoes by blanching in boiling saline solutions

The response surface methodology was applied to investigate the way in which variables, such as time of treatment, sodium or calcium chloride concentrations and lactic acid concentration, affect the blanching of potato slices in boiling solutions. Two 3 factor-5 level, second order central composite designs were developed to analyse the considered variables. Results showed that all the considered blanching treatments allowed polyphenoloxidase inactivation. With regard to colour, the use of calcium chloride, already at low concentrations, would seem better than the use of sodium chloride. Under the applied operative conditions, the best results were obtained with short times of treatment and low lactic acid concentrations.

Specification of a new de‐stoner machine: evaluation of machining effects on olive paste's rheology and olive oil yield and quality

BACKGROUND An industrial prototype of a partial de-stoner machine was specified, built and implemented in an industrial olive oil extraction plant. The partial de-stoner machine was compared to the traditional mechanical crusher to assess its quantitative and qualitative performance. The extraction efficiency of the olive oil extraction plant, olive oil quality, sensory evaluation and rheological aspects were investigated. RESULTS The results indicate that by using the partial de-stoner machine the extraction plant did not show statistical differences with respect to the traditional mechanical crushing. Moreover, the partial de-stoner machine allowed recovery of 60% of olive pits and the oils obtained were characterised by more marked green fruitiness, flavour and aroma than the oils produced using the traditional processing systems. CONCLUSION The partial de-stoner machine removes the limitations of the traditional total de-stoner machine, opening new frontiers for the recovery of pits to be used as biomass. Moreover, the partial de-stoner machine permitted a significant reduction in the viscosity of the olive paste.

Physical and Sensory Properties of Bread Enriched with Phenolic Aqueous Extracts from Vegetable Wastes

The water of the breads was replaced with phenolic aqueous extracts from chicory, cabbage, celery, fennel, olive leaf, or grape marc wastes obtained through microwave-assisted extraction. The highest phenolic concentrations were found in the grape marc and in the bread enriched with it. The highest antioxidant activity values were measured in the crust of bread produced with the grape marc extract and in the crumb of bread with olive leaf extract. Generally, the replacement of water caused significant decreases of the specific volume, the shift of the crumb colour towards redder and yellower tones, and modification of gustatory and tactile attributes.

Phenolic content, physical and sensory properties of breads made with different types of barley wort

BACKGROUND Barley wort, an intermediate product of beer brewing, is rich in phenolic compounds. The aim of this work was to evaluate the possibility of increasing the antioxidant content of bread by replacing water with three types of wort: two of them withdrawn at the end of the mashing operation during the production of a Pilsner and a Double Malt Pilsner beer respectively; the other collected at an intermediate stage of mashing of the Pilsner beer. The chemical, physical and sensory properties of the wort-added breads were compared with those of a control bread. RESULTS All three worts led to increased phenolic content, volume and specific volume of the breads and induced significant changes in 11 of 23 sensory descriptors. The highest phenolic contents were detected in breads made either with the Pilsner wort withdrawn at an intermediate stage of mashing or with the Double Malt Pilsner wort. The former also gave the highest increase in volume and specific volume but significantly reduced the scores for crunchiness, firmness and cohesiveness. The latter led to lower increases in volume and specific volume, but less significant changes in the sensory properties were associated with its use. CONCLUSION Worts can be conveniently used to increase the antioxidant content of bread. However, different types of wort can modify to different extents the physical and sensory properties of the product.

Mobile Elevated Work Platforms versus Ladders in Olive Tree Pruning: Evaluation of Physical Activity and Pruning Performance

The use of mobile elevated work platforms (MEWPs) versus ladders was studied to evaluate the physical activity (PA) of workers and their performance during olive tree pruning. Accelerometers worn by the workers were used to measure triaxial accelerations, which were converted into PA using Freedsons equation. The mean values of acceleration on the three axes for workers on ladders led to statistically higher results than for workers on MEWPs. The energy expenditure (EE) and metabolic equivalent (MET) values were statistically different (about 1.8 times higher) for the ladder work site than for the MEWP work site. The use of an MEWP leads to more time spent on moderate activity (84.30%) than when using a ladder (71.90%) but no time on vigorous activity compared to a ladder (13.88%). The pruning performance was 3.8 for the MEWP and 1.4 for the ladder, while the labor productivity was 11.4 for the MEWP and 4.2 for the ladder. Thus, it is possible to reduce worker employment and costs by about 2.7 times with MEWPs.