Sonia Calligaris

Review of non-enzymatic browning and antioxidant capacity in processed foods ☆

Browning reactions represent an interesting research area for the implications in food technology, nutrition and health. The development of some non-enzymatic browning reactions, such as Maillard reaction, has been recently associated to the formation of compounds with strong antioxidant capacity. In this paper, the relation between colour changes due to non-enzymatic browning and the formation of compounds with antioxidant activity is discussed. Simple positive or complex correlation between colour and antioxidant properties can be found depending on composition and technological history of the product. Complex relations between these variables are generally obtained in multi-component and in formulated foods, where the simultaneous development of a number of reactions, interacting or prevailing Maillard reaction itself, can affect in opposite ways the overall antioxidant properties and colour of the product.

Shelf Life Prediction of Bread Sticks Using Oxidation Indices: A Validation Study

The aim of this study was to apply the protocol for the shelf life prediction of bakery products proposed by Calligaris and others (2007a) on bread sticks. The methodology comprises 4 steps: (1) evaluation of the physical properties of fat; (2) performing the accelerated shelf life test; (3) evaluation of sensory acceptance limit and the relevant chemical index limit; (4) setting up the shelf life prediction model. The results allow validating the shelf life prediction methodology proposed. In fact, the peroxide number was found to be a representative index of the quality depletion of bread sticks during their shelf life. In addition, once again by accounting for the changes in the fat physical state, it is possible to set up a modified Arrhenius equation able to describe the temperature dependence of peroxide formation. Finally, a mathematical model to simply and quickly calculate the shelf life of bread sticks has been developed.

Shelf Life Modeling of Photosensitive Food : The Case of Colored Beverages

A new approach to shelf life modeling of photosensitive foods was developed taking into consideration the example of a saffron-containing yellow beverage highly prone to oxidative photobleaching. The beverage was exposed to different light levels at increasing temperatures. During exposure, samples were analyzed for bleaching rate, pigment content, and pigment degradation products. The results obtained clearly showed that shelf life testing of light-sensitive foods must take into proper account the effect of light. In addition, for these foods, shelf life models based on the sole accelerating effect of temperature may be misleading. By contrast, the concomitant exploitation of the accelerating effects of both light and temperature was used to develop and validate a simple model correctly predicting the shelf life of the beverage under actual storage conditions. The methodology proposed may allow solving of the difficult task of predicting shelf life of photosensitive foods usually marketed in the presence of light.

Use of monoglyceride hydrogel for the production of low fat short dough pastry

The influence of palm oil replacement with a monoglyceride-palm oil-water gel (hydrogel) on physical properties and acrylamide content of a low fat short dough pastry was studied. The effect of the incorporation of the hydrogel was monitored during storage by assessing moisture, firmness, proton density/mobility using magnetic resonance imaging (MRI) and acrylamide content. The use of hydrogel allowed the lipid content of pastries to be reduced with minor effects on their quality characteristics. However, the hydrogel-containing pastries showed a crunchier crust, higher acrylamide content and a higher tendency to staling. As assessed by MRI, these results were ascribable to the development of a peculiar system morphology promoted by hydrogel incorporation in the food matrix.

Shelf-life Assessment of Food Undergoing Oxidation–A Review

Oxidation is the most common event leading to the end of shelf life of microbiologically stable foods. Thus, a reliable shelf-life assessment is crucial to verify how long the product will last before it becomes oxidized to an unacceptable level to the consumers. Shelf-life assessment strategies of foods and beverages suffering oxidation are critically discussed focusing on definition of the acceptability limit, as well as the choice of the proper oxidative indicators, and methodologies for shelf-life testing. Testing methodologies for shelf-life determination under actual and accelerated storage conditions are considered, highlighting possible uncertainties, pitfalls, and future research needs.

Effects of oral administration of silymarin in a juvenile murine model of non-alcoholic steatohepatitis

The increasing prevalence of non-alcoholic fatty liver disease (NAFLD) in adolescents is challenging the global care system. No therapeutic strategies have been defined so far, and changes in the lifestyle remain the only alternative. In this study, we assessed the protective effects of silymarin in a juvenile non-alcoholic steatohepatitis (NASH) model and the in vitro effects on fat-laden human hepatocytes. C57Bl/6 mice were exposed to HFHC diet immediately after weaning. After eight weeks, animals showed histological signs of NASH. Silymarin was added to the HFHC diet, the treatment continued for additional 12 weeks and the effects on BMI, hepatomegaly, visceral fat, lipid profile, transaminases, HOMA-IR, steatosis, inflammation, fibrosis, oxidative stress, and apoptosis were determined. The switch from HFHC to control diet was used to mimic lifestyle changes. In vitro experiments were performed in parallel in human hepatocytes. HFHC diet supplemented with silymarin showed a significant improvement in glycemia, visceral fat, lipid profile, and liver fibrosis. Moreover, it reduced (both in vitro and in vivo) ALT, hepatic inflammation, oxidative stress, and apoptosis. Lifestyle changes restored the control group parameters. The data presented show the beneficial effects of the oral administration of silymarin in the absence of changes in the dietary habits in a juvenile model of NASH.

Omega-3 Enriched Biscuits with Low Levels of Heat-Induced Toxicants: Effect of Formulation and Baking Conditions

Unconventional formulation and baking conditions were exploited for obtaining omega-3 polyunsaturated fatty acids enriched biscuits. A monoglyceride-flaxseed oil–water gel was used to obtain biscuits which had physical and chemical properties analogous to those of a control sample prepared with palm oil. To reduce fat oxidation and acrylamide and furan formation, the dough was baked at different temperature, time and pressure (i.e. varying from 101.33 to 0.15 kPa) conditions according to a central composite design. Baking at high temperature and reduced pressure allowed to obtain biscuits with acceptable water content and colour, while minimizing omega-3 fatty acids oxidation and acrylamide and furan formation. The biscuits best responding to these characteristics were obtained by applying the combination 174 °C-3.99 kPa-45 min. The low pressure generated inside the oven likely exerted a stripping effect towards acrylamide and furan as well as oxygen thus preventing toxicants to accumulate and lipid oxidation to occur. This study highlighted that the use of monoglyceride-flaxseed oil–water gel combined with baking under reduced pressure is potentially applicable at the industrial level to obtain nutritionally enhanced biscuits, while simultaneously preventing the occurrence of degradation reactions and toxic molecules formation. Due to the worldwide diffusion of cereal-based foods, including sweet biscuits, this formulation and process strategy could have a great economic impact.

Optimization of durum wheat bread enriched with bran

Abstract An attempt is made in this study to balance the nutritional and sensory quality of bread. In particular, the formulation of a functional durum wheat bread enriched with bran at high concentration has been developed. Organogel concentration and bran particle size have been used as process variables for bread optimization. Bran concentration was increased at value as high as 15%, thus increasing the nutritional content, even though the sensory quality decreased. Bread was scored barely acceptable at 15% bran concentration. Therefore, the organogel concentration and bran particle size have been optimized to enhance bread sensory quality. Results show that it is possible to prepare bread with a significant bran enrichment without compromising its acceptability by adding proper concentration of organogel and using bran in appropriate particles size.

Application of multi-pass high pressure homogenization under variable temperature regimes to induce autolysis of wine yeasts

The effects of the number of passes and processing temperature management (controlled vs. uncontrolled) were investigated during high pressure homogenization-induced autolysis of Saccharomyces bayanus wine yeasts, treated at 150MPa. Both variables were able to affect cell viability, and the release of soluble molecules (free amino acids, proteins and glucidic colloids), but the effect of temperature was more important. S. bayanus cells were completely inactivated in 10 passes without temperature control (corresponding to a processing temperature of 75°C). The two processing variables also affected the volatile composition of the autolysates produced: higher temperatures led to a lower concentration of volatile compounds. The management of the operating conditions may allow the compositional characteristics of the products to be modulated, making them suitable for different winemaking applications.

Potential of high pressure homogenization to induce autolysis of wine yeasts

High pressure homogenization (HPH) was tested for inducing autolysis in a commercial strain of Saccharomyces bayanus for winemaking. The effects on cell viability, the release of soluble proteins, glucidic colloids and amino acids in wine-like medium and the volatile composition of the autolysates were investigated after processing, in comparison with thermolysis. HPH seemed a promising technique for inducing autolysis of wine yeasts. One pass at 150 MPa was the best operating conditions. Soluble colloids, proteins and free amino acids were similar after HPH and thermolysis, but the former gave a more interesting volatile composition after processing, with higher concentrations of ethyl esters (fruity odors) and lower fatty acids (potential off-flavors). This might allow different winemaking applications for HPH, such as the production of yeast derivatives for wine ageing. In the conditions tested, HPH did not allow the complete inactivation of yeast cells; the treatment shall be optimized before winemaking use.