Tarte aux poireaux

β-Carotene is an organic, strongly colored red-orange pigment abundant in plants and fruits. It is a member of the carotenes, which are terpenoids (isoprenoids), synthesized biochemically from eight isoprene units and thus having 40 carbons. Among the carotenes, β-carotene is distinguished by having beta-rings at both ends of the molecule. β-Carotene is biosynthesized from geranylgeranyl pyrophosphate.β-Carotene is the most common form of carotene in plants. When used as a food coloring, it has the E number E160a. The structure was deduced by Karrer et al. in 1930. In nature, β-carotene is a precursor (inactive form) to vitamin A via the action of beta-carotene 15,15'-monooxygenase.Isolation of β-carotene from fruits abundant in carotenoids is commonly done using column chromatography. It can also be extracted from the beta-carotene rich algae, Dunaliella salina. The separation of β-carotene from the mixture of other carotenoids is based on the polarity of a compound. β-Carotene is a non-polar compound, so it is separated with a non-polar solvent such as hexane. Being highly conjugated, it is deeply colored, and as a hydrocarbon lacking functional groups, it is very lipophilic.

Citric acid is a natural organic acid found in citrus fruits such as lemons, oranges, and limes.

It is widely used in the food industry as a flavor enhancer, acidulant, and preservative due to its tart and refreshing taste.

Citric acid is safe for consumption when used in moderation and is considered a generally recognized as safe (GRAS) food additive by regulatory agencies worldwide.

Diphosphates (E450) are food additives often utilized to modify the texture of products, acting as leavening agents in baking and preventing the coagulation of canned food.

These salts can stabilize whipped cream and are also found in powdered products to maintain their flow properties. They are commonly present in baked goods, processed meats, and soft drinks.

Derived from phosphoric acid, they're part of our daily phosphate intake, which often surpasses recommended levels due to the prevalence of phosphates in processed foods and drinks.

Excessive phosphate consumption is linked to health issues, such as impaired kidney function and weakened bone health. Though diphosphates are generally regarded as safe when consumed within established acceptable daily intakes, it's imperative to monitor overall phosphate consumption to maintain optimal health.

Mono- and diglycerides of fatty acids (E471), are food additives commonly used as emulsifiers in various processed foods.

These compounds consist of glycerol molecules linked to one or two fatty acid chains, which help stabilize and blend water and oil-based ingredients. E471 enhances the texture and shelf life of products like margarine, baked goods, and ice cream, ensuring a smooth and consistent texture.

It is generally considered safe for consumption within established regulatory limits.

Sodium carbonates (E500) are compounds commonly used in food preparation as leavening agents, helping baked goods rise by releasing carbon dioxide when they interact with acids.

Often found in baking soda, they regulate the pH of food, preventing it from becoming too acidic or too alkaline. In the culinary world, sodium carbonates can also enhance the texture and structure of foods, such as noodles, by modifying the gluten network.

Generally recognized as safe, sodium carbonates are non-toxic when consumed in typical amounts found in food.

Cysteine (symbol Cys or C; ) is a semi-essential proteinogenic amino acid with the formula HO2CCH(NH2)CH2SH. The thiol side chain in cysteine often participates in enzymatic reactions, as a nucleophile. The thiol is susceptible to oxidation to give the disulfide derivative cystine, which serves an important structural role in many proteins. When used as a food additive, it has the E number E920. It is encoded by the codons UGU and UGC. Cysteine has the same structure as serine, but with one of its oxygen atoms replaced by sulfur; replacing it with selenium gives selenocysteine. (Like other natural proteinogenic amino acids cysteine has (L) chirality in the older D/L notation based on homology to D and L glyceraldehyde. In the newer R/S system of designating chirality, based on the atomic numbers of atoms near the asymmetric carbon, cysteine (and selenocysteine) have R chirality, because of the presence of sulfur (resp. selenium) as a second neighbor to the asymmetric carbon. The remaining chiral amino acids, having lighter atoms in that position, have S chirality.)