Structural and sensory impact of various emulsifiers in cocoa hazelnut spread formulations.

In this study, the effects of emulsifiers such as lecithin, AMPs, Palsgaard® Oil-Binder and GMS on cocoa hazelnut spread rheology were compared under the same process conditions and formulation. Emulsifiers were added to the formulation separately at rates of 0.3%-0.4%-0.5%. Hardness values in cocoa hazelnut spread were examined at 15-day intervals until the 60th day. In addition, viscosity, rheological analyses, color, spreadability, stability tests, and sensory analyses were performed. In the production of cocoa hazelnut spread, lecithin and AMP have less hardness and lower viscosity, greater fluent consistency, better spreadability, and lower "work of shear" values compared with other emulsifiers. The emulsifier type/ratio difference did not affect the color value statistically. It was determined that the use of Oil-Binder and GMS significantly protected the stability compared with other emulsifiers. During the 60-day storage period, lecithin preserved its hardness properties better than other emulsifiers. When sensory properties were examined, the use of lecithin and AMP in cocoa hazelnut spread samples scored high in brightness, spreadability, mouthfeel, and taste parameters. As a result, lecithin comes to the fore in the use of different types and ratios of emulsifiers in cocoa hazelnut spread production technology.

Correlation of rheology and oral tribology with sensory perception of commercial hazelnut and cocoa-based spreads.

This study examined the effects of spread formulation and the structural/lubricant properties of six different commercial hazelnut and cocoa spreads on sensory perception. Rheology, tribology, and quantitative descriptive analysis (QDA) was assessed by also evaluating the correlation coefficients between the quality descriptor and the rheological and textural parameters. The viscosity was evaluated at different temperatures to better simulate conditions before and after ingestion. Tribological analysis was executed at 37°C to mimic the human oral cavity. The effect of saliva presence and the number of runs on tribological behaviors was investigated. Moreover, textural, calorimetric, and particle size distribution measurements were performed to reinforce the correlation between structural/thermal parameters (e.g., firmness, stickiness, sugar melting point) and sensory aspects. "Visual viscosity," defined as a sensory attribute evaluated prior to consumption, negatively correlated with apparent viscosity measured at 20°C and 10 s-1, whereas "body," defined during oral processing and related to creaminess, positively correlated with apparent viscosity measured at 37°C and 50 s-1. These attributes were mainly influenced by particulate microstructure and solid volume fraction within the formulation. Textural stickiness positively correlated with sensory "adhesiveness" and was related to fat composition and milk powder addition, while "sweetness" was related to sucrose content and sugar melting enthalpy. Tribological data provided meaningful information related to particle-derived attributes, as well as after-coating perception (fattiness/oiliness), thus better predicting food evolution during oral consumption.

Textural, rheological, melting properties, particle size distribution, and NMR relaxometry of cocoa hazelnut spread with inulin-stevia addition as sugar replacer.

This study investigated the influence of substituting 60, 80, and 100% of the sugar in traditional cocoa hazelnut paste (control) formulation with inulin-stevia (90:10, w/w) mixture on textural and rheological characteristics, melting behavior, water activity (aw), particle size distribution (PSD), and color. Textural, rheological, melting properties, and color of samples were analyzed after 1, 2, and 3 months of storage at 11°C. Nuclear magnetic resonance (NMR) relaxometry experiments were also performed to understand the interaction of new ingredients with oil. Replacement of sugar with inulin-stevia gave darker color, reduced Casson yield stress, and changed the textural parameters and melting profile of the samples depending on the level but did not create a remarkable effect on PSD and Casson plastic viscosity. Increasing inulin-stevia content yielded lower aw and higher T2a values indicating decreased mobility of water. Complete removal of sugar caused low spreadability. The results showed that an 80% replacement level yielded a product with similar textural parameters and fat-melting mouth feeling compared to control sample. Cocoa hazelnut spreads prepared with inulin and stevia showed good textural stability during storage.

Optimization of Hazelnut Spread Based on Total or Partial Substitution of Palm Oil.

Palm oil is widely used in the manufacturing of hazelnut-based spreads due to its unique fatty acid and triacylglycerol profile and, thus, its crystallization behaviour, which makes it suitable for use in fat-based spreadable products. An interesting solution that enables the replacement of palm oil is given by oleogels made with high nutritional quality oil. In this study, the influence of the replacement of palm oil with different glycerol monostearate/olive oil-based oleogels, as well as the influence of the different amounts of GMS employed in oleogel preparation, on the oil binding capacity, spreadability, and rheological and sensory parameters of hazelnut cocoa spreads was investigated. A design of experiment (DoE) approach, with the adoption of the D-optimal design, was used to plan the cocoa hazelnut spread formulations, with the aim being to identify the optimal formulation with desirable quality parameters in terms of Casson's viscosity, spreadability, and oil binding capacity. The resulting optimized formulation was identified in a spread characterized by a total replacement of palm oil with an oleogel made of 95% olive oil and 5% GMS.

Rheological and tribological characterization of different commercial hazelnut-based spreads.

Five commercial hazelnut/cocoa spreads with different compositions were tested by rheology/tribology. The impact of each formulation on the structural/lubricant performances was investigated. Rotational/oscillatory rheology was chosen to assess material behavior during flow. Viscosity variation as a function of temperature and chamber geometry was evaluated. Oscillatory mode tests were carried out to obtain information on product viscoelasticity. Tribological analysis was performed at different temperatures aiming at simulating the chewing/swallowing process. All samples were categorized as pseudo-plastic and viscoelastic materials, with the elastic component prevailing over the viscous one. Major differences were detected in terms of consistency index, depending on the total lipid content. Temperature increase enhanced spread fluidity with a decreasing viscosity according to the Arrhenius model (R2 > 0.942) and greater values of activation energy reflecting higher sensitivity to microstructural changes. An inverse relationship between Casson viscosity ηc and sugar/fat ratio highlighted additional correlations between structural parameters and spread formulation. Tribological measurements at 25°C highlighted that, at the initial eating stage, the friction factor (0.112-0.262 at sliding velocity of 8 × 10-6  m/s) was strongly affected by either the amounts of solid fat or hazelnut percentage. Tribological data corroborated the theory for which tribology and rheology cover different domains.