Pietro Rocculi

The use of sodium bicarbonate for marination of broiler breast meat

This study aimed to evaluate marination performances and the effect on meat quality traits of sodium bicarbonate, used alone or in combination with sodium chloride, when compared with sodium trypolyphosphate by using advanced analytical tools, including low-field nuclear magnetic resonance and differential scanning calorimetry. In total, 140 samples (cylindrical shape of 1 × 4 cm size) were obtained from a batch of 24-h postmortem broiler breast meat (Ross 708, females, 47 d old). Six of the groups were used for subsequent marination treatments, whereas the last group was kept as a nonmarinated control. Samples were subjected to vacuum tumbling in a special equipped laboratory rotary evaporator with a 12% (wt/wt) water:meat ratio using 6 marinade solutions: 7.7% (wt/wt) NaCl (S); 2.3% (wt/wt) Na(4)O(7)P(2) (P); 2.3% (wt/wt) NaHCO(3) (B); S and P; S and B; S, P, and B. Samples marinated with bicarbonate alone or in combination (B, SB, and SPB) significantly increased (P < 0.05) the meat pH by approximately 0.7 units compared with that of the control, whereas phosphate alone or in combination with salt increased (P < 0.05) the pH by 0.2 units. The combination containing all of the ingredients (SPB) produced the highest marinade performances; however, SB was able to guarantee a better marinade uptake and water retention ability with respect to that of SP. According to low-field nuclear magnetic resonance, the combined use of B and P with S determined a remarkable increase in proportion of entrapped water into the myofibrillar spaces, while the extramyofibrillar water fraction was not modified. Moreover, water gain following marination does not correspond to an increase in the freezable water amount, as detected by differential scanning calorimetry. In conclusion, B is a very promising marinating agent, and it can be exploited to develop processed poultry products with no added phosphates to match the request to avoid the nutritional drawbacks recently indicated with the use of phosphates.

Calcium and ascorbic acid affect cellular structure and water mobility in apple tissue during osmotic dehydration in sucrose solutions

The effects of the addition of calcium lactate and ascorbic acid to sucrose osmotic solutions on cell viability and microstructure of apple tissue were studied. In addition, water distribution and mobility modification of the different cellular compartments were observed. Fluorescence microscopy, light microscopy and time domain nuclear magnetic resonance (TD-NMR) were respectively used to evaluate cell viability and microstructural changes during osmotic dehydration. Tissues treated in a sucrose-calcium lactate-ascorbic acid solution did not show viability. Calcium lactate had some effects on cell walls and membranes. Sucrose solution visibly preserved the protoplast viability and slightly influenced the water distribution within the apple tissue, as highlighted by TD-NMR, which showed higher proton intensity in the vacuoles and lower intensity in cytoplasm-free spaces compared to other treatments. The presence of ascorbic acid enhanced calcium impregnation, which was associated with permeability changes of the cellular wall and membranes.

Effect of Cold Plasma Treatment on the Functional Properties of Fresh-Cut Apples

Atmospheric double-barrier discharge (DBD) plasma technology is a promising tool in the food industry as an alternative to traditional food preservation methods. However, the effect of the reactive species generated during the treatment on the content of bioactive compounds in food is still little studied, and there are no data concerning potential deleterious effects of DBD-treated foods on human cells. Some functional properties of DBD-treated minimally processed Pink Lady apples were evaluated in comparison with untreated samples through different in vitro and ex vivo tests. Plasma treatment caused only a slight reduction of antioxidant content and antioxidant capacity (up to 10%), mainly limited to the amphiphilic fraction. Noteworthy, treated apple polyphenol extracts did not reduce cell viability and did not suppress the beneficial physiological cell response to oxidative stress in terms of reactive oxygen species production and phase II enzyme activation in human cultured colonocytes.

Moisture adsorption behaviour of biscuit during storage investigated by using a new Dynamic Dewpoint method

The changes in moisture adsorption isotherms of commercial biscuits during storage were investigated by means of a rapid Dynamic Dewpoint Isotherms (DDIs) method. Moreover, the relationships between the changes in moisture content and some quality characteristics of biscuits (moisture, aw, peroxide value - PV and texture) were studied during 92 days of storage at 35 °C. GAB model was used to fit the experimental sorption behaviours. During storage, moisture content and aw of biscuits increased and the obtained isotherms showed modifications in behaviour and shape. Significant changes were observed in PV values and texture, particularly during the first 40 days of storage. The monolayer moisture content, obtained by the BET equation, significantly increased during storage from 1.473 to 2.080 g water 100 g db(-1), probably because of the increase in the active sites for water binding due to the chemical and physical changes of the main components, induced by product ageing.

Physico-chemical and metabolomic characterization of KAMUT® Khorasan and durum wheat fermented dough

Investigations were made in order to evaluate the influence of the flour type, chemical acidification and fermentation on characteristics of doughs obtained with durum wheat and KAMUT® Khorasan flour. Doughs were observed immediately after mixing, 90 and 360 min of leavening at 30 °C. Fundamental rheology, yeasts heat production by isothermal microcalorimetry and the interaction between water and biopolymers by means of time domain nuclear magnetic resonance were evaluated. In addition aromatic metabolite development was followed by means of the combined application of gas-chromatography and electronic nose. KAMUT® Khorasan flour was found to be more suitable than durum wheat for the fermentation processes tested, especially at acidic conditions, as shown by the increase of the volume and the metabolic heat production by yeast. In acidified dough the pattern of volatile metabolites allowed a clear distinction between the types of dough. Moreover the water/starch proton pool was characterized by higher T2 values in the KAMUT® Khorasan samples.

Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR

Osmotic dehydration (OD) is a widely used preservation technique that consists in the reduction in food water activity by the immersion of the biological tissue in hypertonic solutions. The aim of this work was to analyze the effect of pulsed electric fields (PEF) in mass transfer as a pre-treatment of the OD using NMR. In this sense, PEF pre-treatments were done using three different voltages (100, 250 and 400V/cm) and 60 number of pulse. The OD of kiwifruit was carried out in 61.5% of sucrose solution at 25°C, for a contact period from 0 to 120min. The water distribution into the cellular tissue was studied by NMR relaxometry. In conclusion, NMR is an excellent technique for quantifying water molecules according to their interactions in the fruit tissue, obtaining the adsorbed water and opening the possibility to apply the BET model to fit the adsorbed isotherm over the whole range of water activity.

Effect of different new packaging materials on biscuit quality during accelerated storage

BACKGROUND The effect of innovative multilayer packaging materials versus a standard one on biscuit quality was studied during accelerated storage at 25, 35, 45 °C and 50% relative humidity for 92 days. Three different packaging materials were used: metalized orientated polypropylene (OPP)/paper (control); metalized poly-lactic acid (PLA)/paper; metalized OPP with ethylene vinyl acetate pro-oxidant additive (EVA-POA)/paper. EVA-POA additive is used to make the plastic layer biodegradable. Various quality sample parameters (moisture, water activity (aw ), texture, peroxide value (PV), hexanal) were analysed during storage. Rate constants (k) and activation energies (Ea ) of hydration reactions and hexanal formation were calculated. RESULTS No remarkable differences in the evolution of primary and secondary lipid oxidation were observed among differently packed biscuits during storage. All samples maintained PV levels between 4 and 14 meq O2 kg(-1) oil. The product in flexible packaging with PLA reached the highest moisture and aw levels, but they did not significantly and adversely affect the other quality characteristics. CONCLUSION The obtained results demonstrate that the new tested packaging materials were suitable for commercial biscuit storage, having similar performance and preservation effects on the overall product quality to those of the standard one. Furthermore, these results could make a contribution to the food industry, encouraging the use of packaging materials with a negligible environmental impact as an alternative to petroleum-based ones.

Response of Pink Lady® apples to post-harvest application of 1-methylcyclopropene as a function of applied dose, maturity at harvest, storage time and controlled atmosphere storage.

BACKGROUND 1-Methylcyclopropene (1-MCP) is an inhibitor of ethylene reception used in post-harvest treatments to delay fruit ripening. Several factors affect the efficacy of 1-MCP treatments. The effect of a post-harvest treatment with 1-MCP on the quality of Pink Lady® apples as a function of 1-MCP dose, storage time and maturity at harvest was investigated. 1-MCP treatment was further tested in combination with controlled atmosphere (CA) storage. RESULTS 1-MCP limited fruit respiration and softening during storage and was more effective on partially matured fruits and at prolonged storage times. The delaying of 1-MCP on the increase of ripening index was greater on matured fruits at prolonged storage times. The combination of 1-MCP and CA treatments positively affected quality indices of mature apples during 6 months of storage and 7 days of commercial life, with 1-MCP being more effective than CA. 1-MCP and CA showed positive combined effects on firmness and ripening index after 6 months of storage, and on firmness and CO₂ production after a further 7 days of commercial life. CONCLUSION By knowing fruit maturity at harvest and expected storage time it is possible to choose the most suitable 1-MCP dose to meet the market requirements by applying a simple polynomial model.

A New Patented System to Filter Cloudy Extra Virgin Olive Oil

The aim of this investigation was to evaluate the chemical and sensory quality of three extra virgin olive oils (EV1-3) subjected to a new patented system to clarify cloudy oils through the insertion of an inert flow gas (argon) in olive oil mass. For this purpose, several quality parameters were determined on the three clarified (EVC1-3) and untreated (EVNC1-3) samples. In particular, the system patented by the University of Bologna and Sapio (a private company that supplies gas for industrial and research sectors) was applied to a 50 L batch of each oil after its production by a low-scale mill. The EV samples were bottled and stored at room temperature and kept in darkness before analysis. Basic quality indices including free acidity, peroxide value, specific absorption in the conjugated triene region and sensory analysis, as well as the composition of the major (fatty acids) and minor (tocopherols, polar phenols, volatiles, water) compounds were determined after three months of storage. The oxidative stability under stress conditions was also assessed. The main results concern the higher overall quality of the EV samples clarified by the patented system compared to untreated ones. The quantity of water significantly decreased in all clarified samples. Above all, the non-clarified oils showed a tendency to quickly develop off-flavors over time and to decrease their oxidative stability.

Effects of chitosan based coatings enriched with procyanidin by-product on quality of fresh blueberries during storage

The aim of this work was to evaluate the efficacy of an innovative edible coating, based on chitosan from mushrooms enriched with procyanidins extracted from grape seeds, on fresh blueberry quality maintenance, (weight loss, pH, dry matter, colour, firmness and antioxidant activity) and microbial growth, during 14 days of storage at 4 °C. For weight loss, pH and dry matter no relevant differences were detected among the control and the differently coated samples at each considered storage time. Chitosan and chitosan + procyanidins coatings promoted a slight decrease of luminosity and an increase of blue hue colour of blueberry samples during the whole storage period. The use of coating promoted an increase in the antiradical activity that was the highest in blueberries coated with chitosan + procyanidins. Microbiological analysis results indicated that the chitosan-based coated samples had a significantly higher yeast and mould growth inhibition compared to the uncoated sample.