Sensory signature of lignins, new generation of bio-based ingredients in cosmetics.

Lignins represent a high interest in cosmetics as promising multifunctional ingredients. Despite this, uncovering the sensory profile of lignin-based emulsions has remained an unexplored frontier. This study aims to bridge this gap by employing expert sensory evaluation and instrumental characterization to assess the sensory attributes of lignin-based emulsions. A comparative analysis with commercial tinted products and discrimination among lignin derivatives were integral components of the research. Results underscored the distinctive sensory properties of lignin emulsions, exhibiting significantly higher "Integrity of shape" (7.0 ± 0.1) compared to commercial products (4.8 ± 0.1). Additionally, lignin emulsions displayed longer play-time until skin absorption (4.3 ± 0.1), contrasting with the quicker absorption of commercial products (2.7 ± 0.4) and their shorter play-time. Depending on application requirements, lignin derivatives offer formulators a versatile sensory toolbox. Discrimination of lignin emulsions on certain texture properties was achieved using various instrumental tools. Despite the complex formulation of commercial products compared to lignin emulsions, similar texture properties were observed, showcasing lignins' potential to replace multiple ingredients in tinted cosmetics. Beyond their established antioxidant, anti-UV, anti-bacterial, and emulsifying properties, this study reveals additional advantageous sensory properties of lignins, positioning them as promising plant-based sensory ingredients in sustainable cosmetic applications.

Multifunctional active ingredient-based delivery systems for skincare formulations: A review.

Nowadays, there is a growing demand for effective cosmetic skincare products that can address the specific skin problems of consumers. Delivery systems play an important role in the effective action of cosmetic skincare formulations. Delivery systems are attractive and smart technologies used as carriers for cosmetic ingredients, which are sensitive to various physical factors such as light, oxygen, pH and temperature. Delivery systems offer several advantages: transport and protection of sensitive active compounds, controlled and targeted release of active ingredients. Several delivery systems, varying in chemical composition, with adaptable physicochemical characteristics (size, morphology, zeta potential, structure) as well as great advantages as carriers, are developed and described in the literature. This article reviews the current cosmetic active ingredients used in skincare products due to their beneficial properties such as antioxidant, anti-aging, photo-protective, anti-inflammatory, anti-microbial, etc.). In addition, the main advantages of several classes of delivery systems (emulsions, lipid nanoparticles, polymeric particles) are described, as well as some recent approaches used to ensure their efficacy (long-term stability, controlled release of the active, skin penetration/permeation) are reviewed. Finally, new trends to be considered for the development of delivery systems and cosmetic formulations are discussed.

Original tools for xanthan hydrophobization in green media: Synthesis and characterization of surface activity.

Xanthan gum (XG) was modified through esterification using various alkenyl succinic anhydrides in green media. FTIR and NMR spectroscopy confirmed that the alkenyl succinic hydrophobic groups were successfully grafted on octenyl-grafted (XG-C8), dodecenyl-grafted (XG-C12), and hexadecenyl-grafted (XG-C16) xanthan backbone. Grafted chains were evaluated by degree of succinylation (DS). Modification enhance the surface activity of xanthan by decreasing surface tension from 72 until 37 and 58 mN/m due to respectively long alkenyl chain for XG-C16 (DS = 2.2 ± 0.2%) and high grafting rate for XG-C12 (DS = 16.9 ± 1.9%). These original tools are of great interest to optimize both the DS and the properties of xanthan gum by varying reaction parameters like pH range, reaction time and the mole excess of the grafting reagents to xanthan monomeric units.

Bio-sourced polymers in cosmetic emulsions: a hidden potential of the alginates as thickeners and gelling agents.

OBJECTIVE: The present work aims to investigate the impact of the alginates on the texture properties of cosmetic emulsions. For this purpose, five systems were selected: a classical emulsion without polymer and four emulsions containing polymers, as texture modifiers, at the level of 1%. Two different grades of alginates were chosen: one rich in mannuronic acid and one rich in guluronic acid. The objective was also to evaluate the potential of in-situ gelation during formulation. The guluronic rich sample was gelled to evaluate the effect on the texture properties. Finally, alginates-based systems were compared to the xanthan gum as a bio-sourced polymer reference. METHODS: The sensory profile of the systems was established through a combination of prediction models and sensory analysis. The emulsion residual films obtained with natural polymers, Alginates and Xanthan Gum used as thickeners, as well as with the gelled version, were similar. However, the structural differences between polymers intervene during the characterisation of the sensory properties "before" and "during" application. A multi-scale physicochemical analysis was used to explain these differences. RESULTS: Due to a controlled formulation process, the use of the polymers did not affect the microstructure of the emulsion which remained similar to the control one. The main impact of the polymers was observed on the macroscopic level: both alginates showed their unique textural signature, different from the classical Xanthan Gum. Due to weak structural differences, mechanical and textural properties were very close between the mannuronic rich and guluronic rich samples, when not gelled, compared to other emulsions. However, the molar mass and the mannuronic/guluronic acids ratio were proved to be crucial for the stretching and consistency properties, showing that this structural difference may have an impact when products are handled in traction and compression. CONCLUSION: Meanwhile, the viscoelastic properties and the dynamic viscosity were greatly increased for the emulsion containing the gelled version of the alginate when compared to the classical polymers. The emulsion was also more consistent as proved by the textural analysis, pointing at better stability and suspension potential of the gelled emulsion versus the classical one containing the usual natural thickening agents.

OBJECTIF: Ce document vise à étudier l'impact des alginates sur les propriétés de texture des émulsions cosmétiques. À cet effet, cinq systèmes ont été sélectionnés: une émulsion classique sans polymère et quatre émulsions contenant des polymères, qui jouent le rôle de modificateurs de texture, à raison d'une teneur de 1%. Deux grades différents d'alginates ont été choisis : un alginate riche en acide mannuronique et un autre riche en acide guluronique. L'objectif était également d'évaluer le potentiel de gélification in situ pendant la formulation. L'échantillon riche en guluronique a été gélifié pour évaluer l'effet sur les propriétés de texture. Enfin, les systèmes à base d'alginates ont été comparés à la gomme xanthane, prise comme polymère d'origine biologique de référence. MÉTHODES: Le profil sensoriel des systèmes a été établi par une combinaison de modèles de prédiction et d'analyse sensorielle. Les films résiduels d'émulsion obtenus avec les polymères naturels, les alginates et la gomme de xanthane utilisés comme épaississants, ainsi qu'avec la version gélifiée, étaient similaires. Cependant, des différences structurelles entre les polymères se manifestent lors de la caractérisation des propriétés sensorielles « avant ¼ et « pendant ¼ l'application. Une analyse physico-chimique à échelles multiples a été utilisée pour expliquer ces différences. RÉSULTATS: En raison d'un procédé de formulation contrôlé, l'utilisation des polymères n'a pas affecté la microstructure de l'émulsion qui est restée la même que celle du témoin. Le principal impact des polymères a été observé au niveau macroscopique: les deux alginates ont montré leur signature texturale propre, laquelle diffère de la gomme de xanthane classique. En raison de faibles différences structurelles, comparées à d'autres émulsions, les propriétés mécaniques et texturales étaient très proches entre les échantillons riches en mannuronique et en guluronique, lorsqu'ils n'étaient pas gélifiés. Cependant, la masse molaire et le rapport acides gluturoniques/acides mannuroniques se sont avérés essentiels pour les propriétés d'étirement et de consistance, ce qui montre que cette différence structurelle peut avoir un impact lorsque les produits sont manipulés en traction et compression. CONCLUSION: Pendant ce temps, les propriétés viscoélastiques et la viscosité dynamique ont été considérablement augmentées pour l'émulsion contenant la version gélifiée de l'alginate par rapport aux polymères classiques. L'émulsion présentait également une plus grande uniformité, comme le prouve l'analyse texturale, indiquant un potentiel de stabilité et de suspension de l'émulsion gélifiée supérieur à celui de l'émulsion classique contenant les agents épaississants naturels habituels.

Complementary approaches to understand the spreading behavior on skin of O/W emulsions containing different emollientss.

The human skin is a very complex living tissue, in a permanent evolution and self-renewing by constant lipids secretion. The characterization of this biological material is a major concern in dermo-cosmetic and pharmaceutics fields. Understanding the skin interaction with its environment, during application of skincare products, is consequently of genuine interest to better control the different phenomena occurring. In sensory language, the application of products on the skin is defined as the spreading behavior. Five O/W emulsions were formulated with different ratios of two emollients (isohexadecane and stearic acid). Complementary instrumental and sensory analysis of spreading behavior was carried out in vivo on human skin as well as in vitro on non-biological skin surface in order to investigate the impact of two emollients, and their mixtures in the spreadability and penetration of O/W emulsions. A first screening was made to link the physico-chemical properties (polarity, physical state and ratio) of emollients with the spreading behavior on human skin. Then, interesting parameters (the plateau value, its length and the increase of the friction value) from the tribological study on skin were considered to allow deepening the product/skin interactions after application of different emulsions and over time. In the last part of the study, an original method, using non-biological surfaces mimicking the human skin, was successfully tested with very good reproducibility of the spreading behavior. This original tool is of great interest to study the efficacy of new formulas on skin, but also for fundamental research and help performing standardized measurements as well as solving the logistic and safety problems of in vivo studies.

Calcium lactate as an attractive compound to partly replace salt in blue-veined cheese.

In addition to their high sodium content, cheeses are thought to induce an acid load to the body, which is associated with deleterious effects on consumers' health. Our objective was to explore the use of alkalinizing salts in partial substitution of NaCl to reduce both the sodium content and the acid-forming potential of cheese, without altering its sensory properties. Blue-veined cheeses were produced under industrial conditions, using brine salting followed by dry salting with a 4:1 (wt/wt) mixture of calcium lactate:NaCl or calcium citrate:NaCl. Sodium chloride was used in 2 granulometries: coarse (control treatment) and fine, to obtain homogeneous mixtures with the organic salts. Cheeses were then ripened for 56 d. No major appearance defects were observed during ripening. Calcium lactate substitution decreased the Na content of the cheese core by 33%, and calcium citrate substitution increased the citrate content of the cheese core by 410%, respectively, compared with fine NaCl. This study highlighted the substantial role of salt granulometry in sodium content, with the use of the coarse salt reducing the sodium content by 21% compared with fine salt. Sensory profiles showed nonsignificant differences in bitter and salty perceptions of salt-substituted cheeses with calcium lactate and calcium citrate compared with control cheeses. The use of calcium lactate should be considered to reduce the sodium content and improve the nutritional quality of cheeses while maintaining the sensory quality of the products. Alkalinizing organic salts could replace the acidifying salts KCl or CaCl2, which are currently used in salt replacement and are not recommended for consumers with renal disease. The method described here should be considered by cheese-making producers to improve the nutritional quality of cheese. Additional nutritional optimization strategies are suggested.

Draining and salting as responsible key steps in the generation of the acid-forming potential of cheese: Application to a soft blue-veined cheese.

A disregarded nutritional feature of cheeses is their high acid-forming potential when ingested, which is associated with deleterious effects on consumers' health. This work aimed to characterize the acid-forming potential of a blue-veined cheese during manufacturing to identify the main steps of the process involved in this phenomenon. Sampling was performed on 3 batches at 10 steps of the cheese-making process: reception of raw milk, pasteurization, maturation of milk, coagulation, stirring, draining of the curds, and 4 ripening stages: 21, 28, 42, and 56d. The acid-forming potential of each sample was evaluated by (1) the calculation of the potential renal acid load (PRAL) index (considering protein, Cl, P, Na, K, Mg, and Ca contents), and (2) its organic anion content (lactate and citrate), considered as alkalinizing elements. Draining and salting were identified as the main steps responsible for generation of the acid-forming potential of cheese. The draining process induced an increase in the PRAL index from 1.2mEq/100g in milk to 10.4mEq/100g in drained curds due to the increase in dry matter and the loss of alkaline minerals into the whey. The increase in PRAL value (20.3mEq/100g at d 56) following salting resulted from an imbalance between the strong acidogenic elements (Cl, P, and proteins) and the main alkalinizing ones (Na and Ca). Particularly, Cl had a major effect on the PRAL value. Regarding organic anions, draining induced a loss of 93% of the citrate content in initial milk. The lactate content increased as fermentation occurred (1,297.9mg/100g in drained curds), and then decreased during ripening (519.3mg/100g at d 56). This lactate level probably helps moderate the acidifying potential of end products. Technological strategies aimed at limiting the acid-forming potential of cheeses are proposed and deserve further research to evaluate their nutritional relevance.

Exploratory study of acid-forming potential of commercial cheeses: impact of cheese type.

Due to their composition, cheeses are suspected to induce an acid load to the body. To better understand this nutritional feature, the acid-forming potential of five cheeses from different cheese-making technologies and two milk was evaluated on the basis of their potential renal acid load (PRAL) index (considering protein, P, Cl, Na, K, Mg and Ca contents) and organic anions contents. PRAL index ranged from -0.8 mEq/100 g edible portion for fresh cheese to 25.3 mEq/100 g for hard cheese Cantal and 28 mEq/100 g for blue-veined cheese Fourme d'Ambert. PRAL values were greatly subjected to interbatch fluctuations. This work emphasized a great imbalance between acidifying elements of PRAL calculation (Cl, P and proteins elements) and alkalinizing ones (Na and Ca). Particularly, Cl followed by P elements had a strong impact on the PRAL value. Hard cheeses were rich in lactate, thus, might be less acidifying than suspected by their PRAL values only.