**5. Antioxidants of honey**

**Figure 2.** Survival of *Lactobacillus rhamnosus and Lactobacillus paracasei* after gastric and internal condition.

**Figure 1.** Production of probiotic fermented milk added with 5% of honey.

292 Honey Analysis

During recent years, functional foods have attracted growing attention because of consum‐ er's increasing concerns about their health, which has stimulated research effort into such foods [6]. An example, which emphasizes the importance of diet to health, is the French paradox, first observed in French population and found later also in other Mediterranean populations. Epidemiological studies revealed that antioxidant‐rich diet is correlated with the increased longevity and decreased incidence of cardiovascular diseases observed in these populations despite their high fat diet, low exercise and smoking habits. It is well known that antioxidants can contribute to prevention of other illnesses, including neurodegenerative dis‐ eases, cancer and diabetes [32, 33].

Oxidative stress is an imbalance between oxidative and antioxidant molecules. The reac‐ tive species (O2 •‐, •OH, H2 O2 and others) have low stability and high reactivity resulting in low steady‐state concentrations and high diversity of reactions they can participate in. Because of that, oxidative damage induces in biomolecules, as carbohydrates, pro‐ teins, lipids, and nucleic acids, which may alter its function, causing cells damage. As a consequence might flaw tissues and organs, leading to diseases [34]. Despite of their great capacity for damaging cells, other agents play important role, such as real players in many normal functions of living organisms, for instance in signalization of immune system cells [35].

Antioxidants are agents responsible for inhibition and reduction of injuries caused by reac‐ tive species in cell. Our genome encodes antioxidant enzymes to protect against oxidative damage, such as superoxide dismutase, catalase and glutathione peroxidase. Indeed, low molecular weight molecules as tocopherol, ascorbic acid and polyphenols can help on this process.

Free radicals can also affect food quality by reducing its nutritional content, color loss, unpleas‐ ant odors and flavors, promoting the development of food spoilage and, consequently, abbre‐ viating their shelf life. Many synthetic antioxidants have been used in the food industries, but recent researches have mentioned their disadvantages and possible toxic properties for human and animal health [6, 34].

Honey and other bee products, whereby royal jelly and propolis may be used as functional foods because of their naturally high antioxidant potential, which could contributes to the prevention of certain illnesses [36–38]. Ancient Egyptians, Chinese, Greeks and Romans used honey in combination with vegetable or animal fat but also as part of all sorts of ointments [38]. The use of honey in modern medicine was strongly declined due to discovery of new drugs, but the search for more natural treatments boosts again search of honey and other products of bees [39].

Honey is a supersaturated solution of sugars (70–75%), of which fructose (38% w/w) and glucose (31% w/w) are the main contributors, 20–25% of water and about 3–5% for various substances [22, 38]. Hundreds of bioactive substances have already been found in honeys from different regions. This wide variation occurs when honeybees collect nectar from plants, incorporating secondary metabolites product of vegetables. This metabolism is rather vari‐ able and primarily depends on the botanical and geographical origin of the floral source, although certain external factors also play a role, such as seasonal and environmental factors and its processing [22, 40].

Honey antioxidant activity appeared to be a result of the combined effect of a range of compounds. Phenolic compounds (flavonoids and phenolic acids), as well as non‐phenolic (ascorbic acid, carotenoid‐like substances, organic and amino acids, and proteins including certain enzymes such as glucose oxidase and catalase) can contribute to honey antioxidant activity [40, 41].

The honey phenolic compounds are the main antioxidant compounds of honey. They are the phenolic acids and flavonoids, which are considered potential markers of the honey botanical origin. The phenolic acids are divided in two subclasses: the substituted benzoic acids and cinnamic acids. The flavonoids present in honey are divided into three classes with similar structure: flavonols, flavones and flavanones. These are important due to their contribution to honey color, taste and flavor and also due to their beneficial effects on health [21].

Large amount of research in honey also reports strong correlation between the total pheno‐ lic content and the antioxidant activity of honey extracts. Because of that, several literature reports have sought to identify and isolate them. Despite the relevant importance of poly‐ phenolic compounds, which are recognized as the major constituents and responsible for the health‐promoting properties of honey, their identification and quantification are of great interest for understanding their contributions to the overall bioactivity of honey [40].
