Anne Saint-Eve

Quality changes in yogurt during storage in different packaging materials

The influence of packaging polymers (polypropylene or polystyrene) on the sensory and physicochemical characteristics of flavoured stirred yogurts with either 0% or 4%-fat content was investigated during the 28 days of storage at 4°C. Regardless of the packaging type, complex viscosity and thickness perception increased during storage due to exopolysaccharide production, whereas the pH of yogurts decreased. Packaging type had a greater impact on 0%-fat yogurts than on 4%-fat yogurts for both sensory and physicochemical characteristics. During storage, 0%-fat yogurt conditioned in glass displayed the lowest aroma quantity decrease of the three types of packaging, in accordance with the olfactory properties. However, between the two polymer types, polystyrene packaging seemed to be preferable for limiting aroma compound losses and subsequent fruity note intensities, and for avoiding the development of odour and aroma defects. Less significant packaging effect was observed for 4%-fat yogurts.

Influence of Composition (CO2 and Sugar) on Aroma Release and Perception of Mint-Flavored Carbonated Beverages

The aim of the present work was to identify and quantify physical mechanisms responsible for in-nose aroma release during the consumption of mint-flavored carbonated beverages in order to better understand how they are perceived. The effect of two composition factors (sugar and CO(2)) was investigated on both the sensory and physicochemical properties of drinks by studying in vitro and in vivo aroma release. Sensory results revealed that the presence of CO(2) increased aroma perception regardless of the sugar content. In agreement with volatility parameters, in vivo measurements showed that carbonated drinks released a greater quantity of aroma compounds in the nose space than non-carbonated ones. CO(2) seemed thus to induce large modifications of the physicochemical mechanisms responsible for the aroma release and flavor perception of soft drinks. Moreover, sugar content seemed to have an impact (increase) on aroma perception only in the case of non-carbonated beverages. Sensory interactions were thus observed, in particular, between sweet and aroma perceptions. For carbonated beverages, sugar content had an impact only on aroma release, but not on their perception.

Retention of aroma compounds: an interlaboratory study on the effect of the composition of food matrices on thermodynamic parameters in comparison with water

BACKGROUNDnPartition coefficients give an indication of the retention of aroma compounds by the food matrix. Data in the literature are obtained by various methods, under various conditions and expressed in various units, and it is thus difficult to compare the results. The aim of the present study was first to obtain gas/water and gas/matrix partition coefficients of selected aroma compounds, at different temperatures, in order to calculate thermodynamic parameters and second to compare the retention of these aroma compounds in different food matrices.nnnRESULTSnYogurts containing lipids and proteins induced a higher retention of aroma compounds than model gel matrices. The observed effects strongly depend on hydrophobicity of aroma compounds showing a retention for ethyl hexanoate and a salting out effect for ethyl acetate. A small but noticeable decrease in enthalpy of affinity is observed for ethyl butyrate and ethyl hexanoate between water and food matrices, suggesting that the energy needed for the volatilization is lower in matrices than in water.nnnCONCLUSIONnThe composition and complexity of a food matrix influence gas/matrix partition coefficients or aroma compounds in function of their hydrophobicity and to a lower extent enthalpy of vaporization.

Chapter 28 – Influence of Composition (CO2 and Sugar) on Aroma Release and Perception of Mint-Flavored Carbonated Beverages

The aim of this study was to quantify the effects of sugar and CO2 contents on the sensory and physicochemical properties of mint-flavored carbonated beverages, combining sensory and instrumental dynamic methods. Sensory results revealed that the presence of CO2 increased aroma perception regardless of the sugar content. In agreement with volatility parameters, in vivo measurements showed that carbonated drinks released more aroma compounds in the nose space than non-carbonated ones. Sugar content increased aroma perception only in the case of non-carbonated beverages, highlighting the existence of sensory interactions between sweet and aroma perceptions. For carbonated beverages, sugar content had an impact on aroma release, but not on aroma perception.

Chapter 2 – The Dynamics of Aroma Release during the Consumption of Candies with Different Structures: Relationship with Temporal Perception

This chapter aims at investigating the role of candy texture on the dynamics of aroma release using dynamic instrumental and sensory methods. The highest in vivo release, monitored using proton transfer reaction mass spectrometry (PTR-MS), was obtained for the 2% gelatin sample for all aroma compounds. The temporal dominance of sensations (TDS) method highlighted that the dominant sensation for the liquid product was the “strawberry” note. For other products, the temporal characteristics of perceptions were more complex. Data highlighted that aroma release resulted from interaction between product properties and oral behavior. Some relations with the dynamics of perception have been established, essentially between temporal parameters.

Chapter 98 – Impact of Swallowing on the Dynamics of Aroma Release and Perception During the Consumption of Alcoholic Beverages

An integrated approach combining sensory analysis and physicochemistry was used to investigate the impact of swallowing on aroma release and perception. A panel of 10 people evaluated the dynamics of aroma perception during the consumption of a commercial flavored vodka, using two protocols (spitting out or swallowing the product) and the temporal dominance of sensations method. Aroma release in their nasal cavity was simultaneously measured by proton transfer reaction mass spectrometry. The swallowing of the product resulted in more complex perceptions, but decreased the dominance rates of aromatic attributes. Ethanol perception also had a high impact when the product was swallowed.