Massimiliano Rinaldi

The effect of different convection cooking methods on the instrumental quality and yield of pork Longissimus dorsi

The effect of different cooking methods (natural convection, NC, forced convection, FC and forced convection/steam combined, FC/S) on selected physical properties of cooked pork Longissimus dorsi samples were compared. FC/S treatment was significantly faster (∼19 min) than NC and FC cooking treatments (∼27 min). The overall cook values at the center of all samples (calculated taking into consideration the cooling phase) were comparable and might explain the similar tenderness found among samples that underwent significantly different thermal histories. The weight loss of the FC/S samples was significantly higher than in the other cooking methods while the color of the surface was paler than the NC and FC ones.

Effect of postharvest UV-B irradiation on nutraceutical quality and physical properties of tomato fruits

Nutraceutical (ascorbic acid and carotenoids) and physical (colour and firmness) parameters were evaluated in two tomato genotypes (Money maker and high pigment-1) subjected to post harvest UV-B irradiation at different ripening stages (mature green and turning). UV-B treatment increased the concentration of ascorbic acid and carotenoids in Money maker flesh and peel, while high pigment-1 fruits underwent only minor changes, suggesting that hp-1 mutation decreased the fruit ability to respond to UV-B radiation. Colour parameters appeared to be more influenced by harvesting stages than UV-B with the exception of redness (a∗), which in Money maker was found to increase in both flesh and peel of irradiated fruits at turning stage, although not significantly, while control was more red than treated at mature green stage. Firmness was negatively influenced by UV-B, as tomatoes were found to soften after the treatment, although this aspect needs further studies to be clarified.

Impact of the industrial freezing process on selected vegetables — Part I. Structure, texture and antioxidant capacity

In this work, the impact of the industrial freezing process on structure, texture and total antioxidant capacity was studied using green asparagus stems, zucchini and green beans. Samples were analysed as raw/uncooked, blanched, raw/boiled and industrially frozen/boiled. A consistent damage of the vegetable tissue was revealed by the histological analysis on vegetables boiled after freezing. The cells appeared to be dehydrated, contracted and separated at different levels depending on the anatomical structure of each vegetable. The initial textural quality was partially retained in all blanched vegetables, and enhanced in cut tested asparagus stems, in relation to the action of phenolic acids at cell wall level. Raw/boiled and industrially frozen/boiled asparagus stems exhibited comparable forces of penetration and cut tests. On the other hand, zucchini, both raw and frozen, completely softened after boiling making the texture measurement impossible. Industrially frozen/boiled green beans showed higher values of cut and penetration forces, probably due to a higher presence of swollen cell walls, in comparison to those raw/boiled. Blanching and boiling significantly increased the ferric reducing antioxidant power values of asparagus stems and green beans compared to uncooked/raw samples, while boiling after the freezing process significantly deprived both vegetables of the initial antioxidant capacity. On the other hand, boiling the frozen zucchini proved to be detrimental to the antioxidant capacity. In conclusion, manufacturers and researchers should join together to develop specific industrial freezing process conditions according to the matrix of each vegetable.

Evaluation of Pasta Thermal Treatment By Determination of Carbohydrates, Furosine, and Color Indices

The drying process of pasta plays a crucial role in assuring its final quality, since the operational conditions of this process may imply thermal and mechanical damage that also affect final product yield. In this work, independent analyses on furosine, carbohydrates, and color indices (red, yellow, and lightness) have been conducted on pasta samples produced by an Italian pasta factory in order to correlate the examined parameters with pasta drying process. The investigation has been focused on pasta samples having different shapes in order to evaluate how the considered parameters are affected by the specific thermal process scheduled for each pasta format. The same analyses were also performed on semolina used for each pasta sample production, with the aim of verifying whether furosine amount, color indices, and maltulose change in relationship with Maillard reaction (MR) occurring during the drying process. Maltulose presence has been evaluated in semolina for the first time. In addition, the study has been extended to commercial pasta samples of different qualities; a Principal Component Analysis (PCA) has also been conducted to combine together all observed data with the aim of proposing an overall quality index. Finally, a statistical model based on chemical and color parameters as independent variables was successfully developed (R2 = 0.990) by means of a multiple linear regression (MLR) analysis to predict commercial pasta cook values and drying cycles as consequences.

Differential scanning calorimetry thermal properties and oxidative stability indices of microwave heated extra virgin olive oils

BACKGROUND The use of differential scanning calorimetry (DSC) for assessing the deterioration effect of microwave heating on vegetable oils, and on olive oils in particular, has been partially explored in literature. The aim of this work was to evaluate the potential of DSC to discriminate among microwaved extra virgin olive oils (EvOo from different olive cultivar and origin), according to changes on thermal properties (upon cooling and heating) and traditional oxidative stability indices (peroxide, p-anisidine and TOTOX values). RESULTS An elevated value of lipid oxidation was reached by the most unsaturated EvOo sample (9.5% of linoleic acid) at 6 min of microwave treatment. Free acidity significantly increased (0.42%) only for the oil sample with the highest water content (874 mg kg(-1) oil) at the longest time of treatment. Crystallisation enthalpies significantly decreased and the major exothermic peak shifted towards lower temperature, leading to enlargement of the transition range in all samples due to the formation of weak and mixed crystals among triacylglycerols and lipid degradation products. On the contrary, thermal properties upon heating appeared to similarly vary among samples. CONCLUSIONS The analysis of DSC thermal properties upon cooling seemed to clearly discriminate among different EvOo samples after microwaving. The relation between changes of thermal properties and oxidation parameters should be further studied using additional oxidative stability indices on a larger set of oil samples, due to the complexity of EvOo composition.

Stability of iodine during cooking: investigation on biofortified and not fortified vegetables.

Abstract Biofortification of food crops through fertilization and salt iodization are key strategies for the prevention and control of iodine deficiency disorder. However, considerable losses of iodine can occur during processing. In this study, the stability of iodine in biofortified potatoes, carrots and tomatoes was evaluated during different domestic cooking procedures, as this matter was poorly discussed in literature. The stability of iodized salt during baking and boiling of carrots and potatoes not fortified was also investigated. All the adopted cooking procedures have proven to be suitable to preserve the iodine content in biofortified vegetables. During boiling test with iodized salt, neither potatoes nor carrots were able to absorb iodine added with salt, probably owing to the losses occurred during cooking. On the contrary, baking test on potatoes has not caused a significant degradation of iodized salt, and no significant differences in iodine concentration were detected before and after cooking.

Effects of alternative steeping methods on composition, antioxidant property and colour of green, black and oolong tea infusions

Cold water steeping is reported to maximise tea health benefits, but requires long infusion time. In this work, the employment of a brief hot infusion step followed by ice addition was evaluated. The comparison of this innovative method with hot and cold steeping was investigated on green, black and oolong teas. Catechins, xanthines and gallic acid content, antioxidant power, total phenolics and colour analysis were evaluated. Hot infusion shown rapid extractive power, but relevant compound degradation. On the contrary, cold infusion extracted higher level of healthy molecules with slow kinetic. The innovative method achieved in short time similar properties of cold infusion in terms of antioxidant power. As for bioactive compounds, such as gallic acid and epigallocatechin gallate, highest values, about double than in hot infusion, were recorded for green and black teas. This steeping method may represent an alternative approach for industrial beverage preparation.

Sourdough fermentation and chestnut flour in gluten-free bread: A shelf-life evaluation

The effect of sourdough fermentation combined with chestnut flour was investigated for improving technological and nutritional quality of gluten-free bread during 5day shelf life by means of chemico-physical and nutritional properties. Sourdough fermentation by itself and with chestnut flour reduced volume of loaves and heterogeneity in crumb grain. Sourdough technology allowed increasing crumb moisture content with no significant variations during shelf-life. Chestnut flour darkened crumb and crust while no effects on colour were observed for sourdough. Sourdough and/or chestnut flour addition caused a significant increase in crumb hardness at time 0 while a significant reduction of staling was observed only at 5days, even if a decrease in amylopectin fusion enthalpy was observed. The percentage of hydrolysed starch during in vitro digestion was significantly reduced by sourdough fermentation with a presumable lower glycaemic index.

Short‐term storage evaluation of quality and antioxidant capacity in chestnut–wheat bread

BACKGROUND Bread traditionally made from wheat is now often supplemented with alternative functional ingredients as chestnut flours; no data have been previously published about the staling of chestnut-containing bread. Thus short-term storage (3 days) for chestnut flour-supplemented soft wheat bread is evaluated by means of selected physicochemical properties (i.e. water dynamics, texture, colour, crumb grain characteristic, total antioxidant capacity). RESULTS Bread prepared with a 20:80 ratio of chestnut:soft wheat flours maintained its moisture content in both crust and crumb. Crumb hardness, after baking, was found to be significantly higher than that of the soft wheat bread; it did not change during storage, whereas it significantly increased in the control bread until the end of the shelf life. The supplemented bread presented a heterogeneous crumb structure, with a significant decrease in the largest pores during shelf life, relative to the shrinkage of crumb grain. The control exhibited a significant redistribution of crumb holes, with a decrease in the smallest grain classes and an increase in the intermediate ones, most likely caused by cell wall thickening. The colour of the crumb remained unaltered in both breads. The crust of the control presented a significant decrease of a* (redness) and that of the supplemented bread exhibited a decrease of b* (yellowness). The antioxidant capacity was detected after day 1 of storage in the chestnut flour bread only. CONCLUSION Chestnut flour supplementation could represent a feasible way of producing bread with improved characteristics, not only just after baking but also during shelf life.

Durum and soft wheat flours in sourdough and straight-dough bread-making

In the present work, the bread-making performance of durum wheat flour under straight-dough and sourdough procedures were compared to those offered by soft wheat flour by means of selected physical properties (colour, texture, water dynamics, crumb grain characteristic, bulk volume) immediately after baking and during a 5-day shelf-life. The use of sourdough process better preserved both crumb grain characteristic and moisture content of the breads during shelf-life, independently of the wheat flour used. The flour seemed to significantly affect the water dynamics in sourdough breads, being the dehydration process of crust and under-crust faster in durum wheat breads. On the other hand, increasing trend of crumb firmness during the shelf-life was slower in durum wheat breads than in those obtained with soft wheat flour. Initial colour parameters of crust and crumb appeared to less change during shelf-life if durum wheat flour was used. Thus, the final quality of breads after baking and along the shelf-life was significantly affected by both the type of flours and the bread-making process. The results reported herein showed that technological performances of durum wheat flour, especially when combined with sourdough processes, could be successfully exploited for the production of innovative products in the bread-making industry.