Elena Curti

Effect of Formulation on Physicochemical Properties and Water Status of Nutritionally Enriched Fresh Pasta

A standard fresh pasta formulation (STD, the control sample) was modified by introducing soy and carrot ingredients both in dry and in liquid forms (soy and carrot flour and soy milk and carrot juice) to obtain eight nutritionally enriched fresh pasta samples with different formulations. The effect of formulation on selected physicochemical properties and water status of fresh pasta were studied. Colour, texture (force at rupture and extensibility), and cooking loss were found significantly affected by the formulation. Soy and carrot decreased the force at rupture and extensibility of fresh pasta and increased the solids loss during cooking. Improper gluten network development due to either a steric hindrance of soy and carrot solids or improper water availability for gluten hydration due to different water–solid interaction developed were hypothesized. Soy and carrot ingredients significantly altered the water dynamics in the pasta matrix at different space-time levels (macroscopic, moisture content and water activity; macromolecular, frozen water content; molecular, proton nuclear magnetic resonance relaxometry) of fresh pasta in a manner dependent upon the physical state of the added ingredient. Soy flour increased both the frozen water content and the overall proton mobility (1H FID, 1H T1 and T2) of fresh pasta while these parameters did not markedly differed from STD when soy milk was used. The presence of both carrot flour and carrot juice decreased significantly the frozen water content of fresh pasta but, at a molecular level, carrot flour altered the proton molecular mobility, while carrot juice did not.

The use of potato fibre to improve bread physico-chemical properties during storage

Bread staling reduction is a very important issue for the food industry. A fibre with high water holding capacity, extracted from potato peel, was studied for its ability to reduce bread staling even if employed at low level (0.4 g fibre/100 g flour). Physico-chemical properties (water activity, moisture content, frozen water content, amylopectin retrogradation) and (1)H Nuclear Magnetic Resonance molecular mobility were characterised in potato fibre added bread over 7 days of storage. Potato fibre addition in bread slightly affected water activity and moisture content, while increased frozen water content and resulted in a softer bread crumb, more importantly when the optimal amount of water was used in the formulation. Potato fibre also reduced (1)H NMR molecular mobility changes in bread crumb during storage. Potato fibre addition in bread contributed to reduce bread staling.

Physico-chemical properties of ready to eat, shelf-stable pasta during storage

The changes in physico-chemical properties of RTE shelf stable pasta were studied during storage with a multianalytical and multidimensional approach (with special focus on water status) to understand the ageing process in this product. Pasta hardness and amylopectin recrystallisation increased, macroscopic water status indicators and proton molecular translational mobility remained constant, and significant changes were measured in the proton rotational molecular mobility indicators ((1)H FID, (1)H T2) during storage. Since the main changes observed in RTE pasta during storage were similar to those observed in other cereal-based products, it would be interesting to verify the effect of the anti-staling methods commonly used in the cereal processing industry in improving RTE pasta shelf-stability.

The use of two-dimensional NMR relaxometry in bread staling: a valuable tool?

Staling of bread was investigated in terms of physico-chemical parameters and one (1D) and two dimensional (2D) 1H Nuclear Magnetic Resonance (NMR) relaxometry. Physico-chemical properties were consistent with those generally reported for bread staling (crumb moisture loss, decrease in frozen water content, formation of amylopectin crystals, crumb hardening). One dimensional 1H NMR investigation suggested the presence of only one T1 protons population, while T2 was representative of multiple proton populations, that well related to the observed physico-chemical changes. 1H Two dimensional NMR provided an interesting insight of 1H T1 dynamics, as it allowed to discriminate the contribution of five protons pools within the 1H T1 relaxation.

Effect of added ingredients on water status and physico-chemical properties of tomato sauce

Different ingredients (guar, xanthan, carboxy methyl cellulose, locust bean gums, potato fiber, milk, potato and soy proteins) were added to tomato sauce to investigate their effect on its physico-chemical properties. The products were characterized in terms of colour, rheological properties (Bostwick consistency, flow behavior and consistency coefficient), water status (water activity, moisture content) and molecular mobility by 1H Nuclear Magnetic Resonance (NMR). Water activity was significantly decreased only by the addition of potato fiber. Xanthan, locust bean, guar and carboxy methyl cellulose significantly enhanced Bostwick consistency and consistency coefficient. Type of ingredient and concentration significantly affected 1H NMR mobility indicators. Principal component analysis (PCA) indicated that only 1H NMR mobility parameters were able to differentiate the effect of milk protein, xanthan and potato fiber on tomato sauce properties. The information collected in this work provides information to intelligently modulate tomato sauce attributes and tailor its properties for specific applications.

Effect of water and gluten on physico-chemical properties and stability of ready to eat shelf-stable pasta

A multi-analytical and multi-dimensional approach was used to investigate the effect of moisture and gluten on physico-chemical properties of shelf-stable ready to eat (RTE) pasta. Moisture and frozen water contents were not affected by formulation nor storage time. Hardness and retrograded amylopectin significantly increased during storage in all samples, more markedly in pasta with the lowest moisture content. Higher amounts of water and gluten reduced pasta hardening and contributed to control RTE pasta quality. (1)H FID became steeper in all samples during storage, but no effect of high moisture and gluten levels was observed on the mobility of these protons. Three proton T2 populations were observed (population C, population D and population E). Population C and D were not resolved during all storage. (1)H T2 relaxation time of the most abundant population (population E) shifted to shorter times and the amount of protons increased during storage, more importantly in the samples with lower moisture and gluten content.

Structured emulsions as butter substitutes: effects on physicochemical and sensory attributes of shortbread cookies

BACKGROUND Reformulation of foods products to reduce total and saturated fats while maintaining acceptable structure, texture and mouthfeel poses an important challenge to the food industry. In this work, the use of structured emulsions (fibre-induced oil-in-water biphasic systems with reduced total and saturated fats) is proposed to replace butter in shortbread cookies. RESULTS Use of structured emulsions resulted in softer dough that was still workable using a traditional process. Shortbread cookies containing structured emulsions were harder and paler than the butter control but had a significantly reduced saturated fat content. They also received promising scores in the sensory analysis in terms of texture and overall acceptability, despite the butter product still being the preferred sample. CONCLUSION The results of this study indicated that structured emulsions represent a good solution to produce nutritionally improved shortbreads. Optimization of the structured emulsion formulation can provide further improvement of the nutritional, sensory and physicochemical properties of shortbread cookies.