Keywords

3.1 Introduction

Honey is a natural organic material produced by a particular species of bees of the genus Apis from flower nectars (Alvarez-Suarez et al. 2014). It is a sweet, viscous, and flavorful liquid that is high in nutritious content (Havsteen 2002). The transfer of nectar to honey is a process of spewing and evaporation. This is then preserved in honeycomb wax as the primary source of food for honey bee (Adebiyi et al. 2004). The honeycomb consists of hexagonal waxy cells manufactured by the bees to shelter their larvae and store the honey. Beekeepers will take the entire honeycomb out for the honey harvest. The chemical composition of the honey varies depending on the nature of the flora from which the nectar was collected, geographic origin, seasonal and environmental conditions. There are raw honey and pasteurized honey. Raw honey is extracted right out of the hive. It can contain traces of wax and pollen since it is not purified. Pasteurized honey is stored without any impurities. Consumption of fresh honey increases immunity to seasonal allergies. Raw honey is rich in nutrients (Olaitan et al. 2007).

Pollen and nectar are the primary food sources for honey bees. And they are the primary source of proteins and carbohydrates.

Three types of bees are present in the bee hive: the bees of the workers, the bees of the drone, and the bees of the queen. Females that do not breed bees are referred to as worker bees. Queen bee and drone bees develop eggs, and these eggs live in bee hives and form larvae after 3–4 days. The female worker bees are produced from the larva. Mainly sterile female worker bees are found in a typical hive colony. The queen bee will live for up to 3–4 years (Bishop 2005).

3.2 Physical Properties of Raw Honey

Freshly extracted raw honey is very viscous in nature. Depending on the composition and water content, the viscosity of honey varies. It can absorb moisture from the environment. Presence of colloidal particles are responsible for the difference in the surface tension. The surface tension as well as viscosity are accountable for the frothing nature of raw honey (Rueppell et al. 2007).

Liquid honey has different colors from colorless to amber color. The variation in the color depends on the botanical origin, age, and storage. If suspended particles like pollens are present, then the clarity varies. Crystallized form of honey has a light color because of the glucose crystals present in it. Presence of fructose and glucose makes the honey sweet. It has almost same sweetness as that of sucrose. Since the microorganisms do not grow in honey, it can be stored for many years.

3.2.1 Types of Honey Based on the Production Procedures

Based on the production procedures, honey can be classified as extracted honey (made by centrifuging the broodless honey combs), pressed honey (made by pressing the honey combs), drained honey (made by slow draining of the broodless honey combs), and organic honey (made by organic beekeeping). Extracted honey is the most widely marketed honey. Organic honey and natural honey have the same composition. The difference between organic honey and natural honey is that the latter contains no traces of beekeeping pesticides.

3.2.2 Types of Honey Based on the Processing Procedure

On the basis of processing procedures, honey may be classified as normal honey, comb honey, and cut comb honey. Normal honey appears as crystalline form or as liquid form or as a mixture of both. Comb honey usually retailed in the broodless combs itself. Cut comb honey contains small pieces of honey comb in it.

3.2.3 Types of Honey Based on the Origin

According to the Codex Alimenterius

  1. 1.

    Based on the topographical region of the honey production, it can be named, if it is produced within the area.

  2. 2.

    Honey may be named based on the plant or floral source if it is produced mainly from that specific source. It will have the organoleptic, physicochemical, and microscopical characteristics equivalent to that origin.

  3. 3.

    Honey may be named based on the geographical or botanical origin (Bogdanov 2011a).

3.2.4 Types of Honey According to the Botanical Source

Depending on the botanical source, honey may be divided as blossom and honey dew. Each honey type is different from another because of the different sources and different proportions. It can be unifloral or multifloral honey. If the pollen grain is initiated from only one particular plant, it is known as unifloral honey. If there is no dominant pollen type, it is known as multifloral honey. Unifloral honey is more valuable.

3.3 Different Species of Honey Bees

Honey bees are known as one of the primogenital forms of animal life. Honey bees are eusocial, flying creature from the genus Apis of the bee clade. They construct colonial nests using wax for their colonies. In these waxy nests, they produce and store honey. The practice of collecting honey from the wild bee colonies is called beekeeping or apiculture. Seven species of honey bees and 44 subspecies of this were identified in the early twenty-first century. Western honey bee is the best known among these and had been used for the honey making and crop pollination. The bee wax has been used for candle making, soap making, lip balms, and other crafts. The scientific study of honey bees is called as melittology.

The main two species of honey bees have been named as Apis mellifera and Apis cerana.

The Apis mellifera or the European honeybee species are the most widely spread all around the world and utmost commonly collected and sold in the world.

In tropical Asia, Apis cerana is used for making honey most commonly. This honey is almost similar to the mellifera honey in composition and taste. Other common species are Apis dorsata and Apis florea. These honeys are marketed locally not worldwide.

Small honey bees like Apis florea and Apis andreniformis can be seen in southern and southeastern Asia. They make their hives in trees and shrubs, and they are relatively small. Their stings are usually unable to penetrate through the human skin. Therefore, these hives and swarms can be picked up with marginal protection (Arias and Sheppard 2005). Apis florea is completely yellow in color (Wongsiri 1997).

The subgenus Megapis can be very dangerous. They build their hives on tall tree branches, on cliffs, and sometimes on buildings. Honey hunters sometimes robbed their honey and may get stinging from it, and it can be fatal (Nathan et al. 2009).

Africanized bees or killer bees are the crosses of European stock and the subspecies A. m. scutellata which is East African lowland species. These bees do not produce excess honey and are more violent than European bees. These honey bees are known to be more resistant to disease and are very good hunters (Wongsiri 1997).

3.4 Folklore Uses

Honey has long been recognized to possess various medicinal properties, and it is used as a wound dressing and as an antiseptic since ancient times. Honey is being used in the traditional medicine since stone age (Needham 2008). Honey is considered as the oldest traditional medicine which has been used for various human diseases worldwide (Fig. 3.1). Some are listed below.

Fig. 3.1
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Folklore use of honey used in different medicine systems

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3.4.1 Honey in Indian System

According to Ayurveda, the ancient system of Indian medicine, honey, without changing its own properties, stimulates the activities of the substances to which it binds. In Ayurveda, honey was used both internally and externally for nutritional and therapeutic uses since hundreds of years. Externally honey was applied for ophthalmic ailments and for wound healing. Internally it was used mainly for cough and asthmatic problems. Honey was used as a base for these cough preparations along with other herbs. It is being used to treat sleep disorders since it has hypnotic action (Murty 2001). Honey has been used in Ayurveda to improve the oral hygiene and to keep the gums healthy (Vaidya et al. 2002). Alvarez-Suarez et al. reported that the consumption of newly formed and collected honey may increase the body weight and stored or old honey can decrease the fat of the body and therefore reduces the body weight (Alvarez-Suarez et al. 2012). In Ayurveda, honey is used as a medicine for the eyes and for the vision, and it reduces thirst, poises hemostasis, and decreases the toxicity. It is used for urinary tract disorders and also for diabetes. Honey is used to stop hiccups, worm infestations, skin disorders, diarrhea, nausea, and vomiting and also for bleeding complaints. Honey speeds up the healing process, and it has been used for the wound healing since long and also for cleaning the wounds (Eteraf-Oskouei and Najafi 2013). According to this system, hot honey can cause toxic effect so it should not be heated or consumed when it is warm (Megan Ware 2015). In Ayurvedic preparations, honey is used as a vehicle or as a preservative (Zumla and Lulat 1989).

3.4.2 Honey in Egyptian System

Ancient Egyptian medicines utilized the medicinal properties of honey. They combined honey with wine and milk and used for many ailments. They offered honey as a sacrifice to their deities in older times (Dash 1972). For embalming the dead bodies, they used honey. Honey was used to heal the infected wounds because of its antibacterial properties. For the topical application, they used honey (Molan 1999).

3.4.3 Honey in Greek System

Ancient Greek people used honey in a drink called Oenomel along with unfermented grape juice. It has been used to treat gout and certain nervous disorders (Dash 1972). Also they used honey for topical antisepsis, contraception, eye diseases, wound healing, cough and sore throat, laxative action, baldness, prevention, and management of blemishes (Molan 1999).

3.4.4 Honey in Islamic Medicine

According to Islamic medicine, honey is used as a healthy drink. The holy Qur’an intensely demonstrates the possible therapeutic values of honey. They used honey for a variety of medical problems, including stomach ailments. They used the beeswax to prevent from cold during winter (Molan 1999).

According to Unani Medicine, honey is used as a natural food supplement, as a nutritive agent, and as antibacterial and anti-inflammatory agent, and it also has wound healing properties (Molan 1999).

3.5 Phyto-Constituents

Pure honey is one of the most essential classes of composites found in plants, containing different identified varieties of primary and secondary metabolites (Fig. 3.2). Some of them are described below.

Fig. 3.2
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Phyto-constituent profile of honey

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3.5.1 Carbohydrates

The general chemical formula of simple sugars is CnH2nOn. It is the fundamental source of energy for cells and among the four major classes of biomolecules (Dilworth et al. 2017; Lee 2007). Carbohydrates are expressed as monosaccharaides, disaccharides, polysaccharides, oligosaccharides, as well as glycoconjugates (Wong and Bryan 2003). Honey carries an array of carbohydrates including monosaccharides which makes up 75% of the carbohydrate content, like glucose and fructose, disaccharides such as maltose, sucrose, and palatinose making up 10–15%. Honey owes it sweet flavor to the high concentration of carbohydrates present, and there are nearly 30 complex sugars, taking up 80–83%, therefore making honey an excellent energy source (304 Kcal/100 g) (Sarfraz et al. 2018; Celestino Santos and González-Paramás 2017). Fructose is the superior sugar constituent in the majority of honeys although some exceptions are present in which glucose is the dominant monosaccharide, such as in uniflower honey like rape honey and dandelion honey. About 8–10% of disaccharides present constitute maltose, isomaltose, kojibiose, and turanose. Due to invertase enzyme action, sucrose is present in less than 30% of the total sugar content. Melezitose, erlose, and raffinose are trisaccharides that are present in relatively high amounts in honeydew honey, nevertheless origin/botanical sources of honey can influence its sugar content (Celestino Santos and González-Paramás 2017).

Fructose being the major constituent contains many benefits including evidence in aiding in diabetes, reducing hyperglycemia in rodents, diabetic patients, and healthy subjects (Vaisman et al. 2006; Kwon et al. 2008). Fructose was found to slow down gastric emptying time and absorption; furthermore, studies show that fructose decreases food ingestion which in turn causes the gastric emptying delay (Kashimura and Nagai 2007; Lina et al. 2002; Thibault et al. 1997). Decreased food intake due to fructose has further shown an impact on the selection of macronutrients for absorption (Gregory et al. 1989; Henry et al. 1991). With decreased food intake comes the suggestion that fructose aids in weight loss; a recent study shows that administering supplements of fructose in low or moderate concentrations to obese subjects shows effective weight loss (Madero et al. 2011). Albeit some studies suggest that fructose intake causes an increase in weight hence the results are inconclusive (Bocarsly et al. 2010; Meirelles et al. 2011; Lavin et al. 1998; Anderson and Woodend 2003).

The second major constituent after fructose is glucose. Although it does not have as many effects as fructose, it aids in the absorption of fructose, and the best results were found when equal amounts of glucose and fructose are given as glucose has a synergistic effect however fructose does not enhance the absorption of glucose (Jones et al. 2011; Fujisawa et al. 1991).

Several studies reported that high-fat-fed rats exhibited a decrease in the amount of intestinal bifidobacteria, and those treated with oligofructose present in honey showed an increase in bifidobacteria with enhanced glucose tolerance in addition to glucose-induced insulin secretions (Cani et al. 2007). Monosaccharides join together to form oligosaccharides (Bogdanov 2008; Erejuwa et al. 2012). Several research studies on honey have revealed that it can multiply the amount of Lactobacillus, Bifidobacterium bifidum, and Streptococcus thermophilus. Evidence has shown that large amounts of fructose and glucose present in honey can increase the development of gastric microflora (Shamala et al. 2000; Chick et al. 2001). Finally, honey varieties that are fructose-rich are considered as a beneficial alternative to high GI sweeteners in the management of diabetes as well as cardiovascular ailments (Bogdanov 2011a; Deibert et al. 2010;). The chemical structure of these compounds are summarized in Fig. 3.3 (Celestino Santos and González-Paramás 2017).

Fig. 3.3
figure 3

Chemical structures of few carbohydrate derivatives present in different types of honey

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3.5.2 Proteins

Honey contains 20 non-enzymatic proteins (0.1–0.5%), comprising albumins, globulins, proteases, and nucleoproteins common to all honey forms. The amino acid content is one fifth of the total content (Gonzalez-Paramas et al. 2006; Sajid and Azim 2012; Hermosın et al. 2003). A free amino acid namely proline is found in honey very commonly (50–85%) (Belitz et al. 2009; Hermosın et al. 2003). Proline is an indicator for botanical origin of honey, and it originates from the salivary secretions of honey bee (Biino 1971). Proline shows a significant role in regulating the nectar enzymatic transfer, in the process of converting the flower nectar into honey (Ortiz-Valbuena and Silva-Losada 1991). Furthermore, a few researchers analyze proline as an indicator for the adulteration of honey with sugar (Bogdanov et al. 1999). Table 3.1 shows the summary of various amino acids present in honey (Doner 2003).

Table 3.1 List of various chemical components present in various types of honey
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The enzymes such as glucose-oxidase, diastase, and invertase are mostly found in honey along with other enzymes like β-glucosidase (White Jr 1979). Invertase causes honey to be a high energetic food (Crane 1980; Sancho et al. 1991). It hydrolyzes sucrose into fructose and glucose, and it also produces some oligosaccharides in an intermediate step therefore making it an important enzyme which keeps its activity after extraction and during storage (White Jr and Maher 1953).

Diastase value is regulated by many legislations as it is utilized as an indicator for the freshness of honey as it is resistant to heat and provide accurate results. Moreover, diastase produces smaller carbohydrates by hydrolyzing starch and dextrin (Crane 1980; White Jr 1978). The presence of an enzyme glucose oxidase causes increased acidity of honey. Conversion of glucose to gluconolactone also facilitate by this enzyme, which results in the formation of gluconic acid along with minor quantity of hydrogen peroxide which accounts for honey’s microbial resistance (White Jr et al. 1963). Glucose oxidase is inactivated at 60 °C and light sensitive (425–525 nm) (Gonzalez 2002; Ortiz-Valbuena and Silva-Losada 1991).

Some other enzymes found in honey though at lower concentrations include B-glucosidase, an enzyme added by bee secretions that hydrolyzes glycosidic toxins ingested by honey bee and transforms β-glucans into oligosaccharides and glucose (Labropoulos and Anestis 2012). In addition to B-glycosides catalase and phosphates and proteases are present. Catalase produces water and oxygen by converting the hydrogen peroxide produced (Huidobro et al. 2005); acid phosphatase can also be used as an indicator, it produces inorganic phosphate from organic phosphate although phosphatase is used as an indicator for fermentation, the optimum pH for its action is between 4.5 and 6.5 (Alonso-Torre et al. 2006). Finally, there are proteases that yield peptides of lower molecular weight by hydrolyzing polypeptides and proteins as well as esterases that breakdown esters (Labropoulos and Anestis 2012).

3.5.3 Organic Acids

These are essential for the preservation of honey, odor, color, and taste, making it difficult for microorganisms to grow therefore preserving it. Organic acid constitutes less than 0.5% of total solids although they also contribute in electric conductivity and honey acidity (Ananias et al. 2013; Bogdanov 2011b). Organic acid is in equilibrium along with the respective lactone (Gomes et al. 2010; White Jr 1979), and it represents 70–90% of the total organic acid. These lactones are produced with the help of an enzyme called glucose-oxidase from glucose (Bogdanov 2011b; Mato et al. 2003). Various organic acids present in honey are listed in Table 3.1 (Bogdanov 2011c).

The value of citric acid compared to gluconic acid indicates if the honey is from floral or honeydew sources (Selvaraj et al. 2006). The malic, gluconic, and citric acids present in honey can chelate with metal ions and strengthen the antioxidant activity of flavonoids (Aazza et al. 2013). A study directed by Cavie et al. tested the free acidity of 35 Spanish honeys for 30 months with no heat and analyzed every 5 months. During the first 5 months, the free acidity remained the same with a very slight increase. The sample started to show a constant increase in free acid after 20 months although it may vary widely. Increased acidity of honey shows the fermentation due to the conversion of alcohol and sugars by honey yeast into acids (Hemadi et al. 2013).

3.5.4 Vitamins

Trace the amount of vitamins found in honey, and it comprises more water-soluble vitamins than fat-soluble vitamins as well as contains very small amounts of lipid substances (Hemadi et al. 2013; Rahman et al. 2014). The various vitamins present in honey are listed in Table 3.1 (Hemadi et al. 2013). Vitamins C and E are known to have antioxidant activity (Bogdanov et al. 2008). Vitamin E, also known as an antioxidant, is reported to increase antioxidant activity and decrease protein oxidation and lipid peroxidation throughout the small intestine (Shirpoor et al. 2007) and reduces glycosylated hemoglobin and fructosamine (Selvaraj et al. 2006; Ceriello et al. 1991; Vinson and Howard 1996). For the regeneration into their antioxidant form as they are pro-oxidants, these vitamins need anti-oxidants (Halliwell 1996; Bowry et al. 1992). It was reported that pure natural honey may cause healing effects and an induction in its cardio protective (Rakha et al. 2008; Khalil and Sulaiman 2010). All the complex B vitamins and vitamin C are mainly derived from pollen; these vitamins can be influenced by filtration as well as by oxidation reactions carried out by glucose oxidase (Ciulu et al. 2011; Rahman et al. 2014). High-performance liquid chromatography-reverse phase (HPLC-RP) is used for the determination of five water-soluble vitamins in honey (Hemadi et al. 2013). Vitamin E has been reported to be successful in reducing programmed cell death and necrosis in noise-affected cells (Leon-Ruiz et al. 2013).

3.5.5 Phenolic

Phenolics are the groups of compounds that are present in plants. Over 8000 diverse structures of phenolics have been found (Estevinho et al. 2008; Bravo 1998). Phenolic compounds found in plants have been reported to be responsible for various therapeutic activities such as anti-inflammatory and anti-atherogenic (Vinson et al. 1998). Phenolic compounds can indeed be divided into flavonoids and phenolic acids, and honey is rich in both flavonoids and phenolic acids (Fig. 3.4), serving as a reference to the biological source of honey (Yao et al. 2003). Honey possesses strong antioxidant activity due to the presence of phenolic compounds or polyphenols generated as secondary metabolic components, which may differ with floral source (Kucuk et al. 2007; Pandey and Rizvi 2009). For instance, specific phytochemicals such as hesperetin and quercetin have already been discovered in citrus and sunflower honey (Anklam 1998; Ferreres et al. 1993; Tomás-Barberán et al. 2001; Aljadi and Kamaruddin 2004). The total phenolic content could be measured as gallic acid equivalent, and the total phenolic content in Indian honey is approximately 65.06 GAE/100 g and in Rhododendron honey is between 0.24 and 141.83 mg GAE/100 g (Bertoncelj et al. 2007; Jaganathan et al. 2010; Silici et al. 2010; Pontis et al. 2014). Different studies indicate that somehow the phenolic compounds found in honey are accountable for different beneficial effects (Turkmen et al. 2005), and techniques such as TLC, HPLC, GC, CE, and colorimetric assays were also used to evaluate polyphenols in honey and propolis and are separated according to environmental conditions (Alvarez-Suarez et al. 2009; Alvarez-Suarez et al. 2012; Trautvetter et al. 2009). Phenolic compounds which are present in Spanish honey for industrialized thermal processing as well as further liquefaction change to caffeic acid and for liquefaction, and further pasteurization contribute to β-coumaric acids (Escriche et al. 2014). Depending on molecular properties, polyphenols can be classified into different categories (Grassi et al. 2010; Tomás-Barberán et al. 2001), phenolic acids comprise only one phenolic ring in their molecules and are also known as non-flavonoid polyphenolic compounds (Grassi et al. 2010; Amiot et al. 1989; Ciulu et al. 2016). Phenolic compounds acquire several safe and effective actions like those of antioxidant, antibacterial and antiviral activities, etc. (Zhang et al. 2016; Lampe 1999; Liu 2013). Many various studies also investigated the phenolic profiles in honey and reported a high correlation of phenolic content with antioxidant (Anand et al. 2018; Saxena et al. 2010).

Fig. 3.4
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Chemical structures of few phenolic compounds present in various types of honey

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3.5.6 Flavonoids

Flavonoids are present in honey in high amounts and constitute a few thousand compounds making up to 50% of the total phenolic compounds, with a prevalent C6-C3-C6 phenylchromane skeleton, and are known for their antioxidant effect. Various categories of flavonoids are present in honey, such as flavanes, flavonols, and dihydroflavonols, based on oxidation levels; the components of flavonoids differ among honeys from different parts of the world or botanical origins (Tomás-Barberán et al. 2001). Table 3.2 summarizes some of the phenolic and flavonoid compounds present in different types of honey (Kassim et al. 2010; Hussein et al. 2011; Eraslan et al. 2010; Petrus et al. 2011). In most of those varieties of honey, hesperetin and naringenin have been identified. However, flavonoids, such as isorhamnetin, alangin, kaempferol, quercetin, and luteolin, have been reported in most honey varieties (Petrus et al. 2011), and catechin has been identified as a prevalent flavonoid in some of Malaysia’s honey that has already been explored (Khalil et al. 2011). Several findings have documented that honey inhibits cellular damage and prevents cell oxidation of cell membrane (Beretta et al. 2007). Antioxidant activity might also be linked to certain other actions, such as increased lipid metabolism and weight loss in human or rat subjects treated with honey (Busserolles et al. 2002; Razquin et al. 2009). The number and orientation of the hydroxyl group and perhaps even the substituents and glycosylation of that same compound determine the antioxidant function of the flavonoid. Glycolysation reduces antioxidant activity particularly in comparison to aglycones.

Table 3.2 Various flavonoids present in different types of honey
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Quercetin and kaempferol are flavonoids that have a statistically significant effect on heart disease and those whose amount relies on its geographic origin (Alvarez-Suarez et al. 2013). Flavonoids are suggested to minimize the risk of cardiovascular disease through three main mechanisms of action: enhancing vasodilatation, the ability of blood platelets to coagulate, and preventing low-density lipoprotein oxidation (Khalil et al. 2011).

According to a study done by Viuda-Martos et al., it has been shown that galangin is effective against herpes simplex virus and coxsackie B virus, while quercetin and rutin show antiviral activity against herpes simplex virus, syncytial virus, poliovirus, and sindbis virus. Never before has the less unambiguous relation among honey and its chemical compounds been formally reported for its antiviral properties (Viuda-Martos et al. 2008). Studies have shown that certain flavonoids are effective of suppressing sodium-dependent, stimulated migration of monosaccharides into intestinal epithelial cells (Kimmich and Randles 1978). Flavonoids, such as quercetin, chrysin, and galangin, have been shown to minimize the activity of pro-inflammatory enzymes such as cyclooxygenase-2 and prostaglandin, and inducible nitric oxide synthase (Murtaza et al. 2014). Flavonoid content in honey has been shown to reduce matrix metallopeptidase-9, which is an inflammatory mediator leading to chronic inflammation (Candiracci et al. 2012). The first and most important activities of flavonoids are their cytotoxic activity. Standard flavonoid Chrysin has been shown to induce apoptosis (Kasala et al. 2015) in rectal and hepatocellular cancer cell lines used levels ranging from 40 to 100 μm (Ronnekleiv-Kelly et al. 2016; Zhang et al. 2016; Li et al. 2011).

In breast, prostate, and lung cancer cell lines, low levels (10 μm) were successful (Samarghandian et al. 2011; Huang et al. 2016), Chrysin induces apoptosis by caspase activation and Akt inactivation in U937 leukemia cells (Woo et al. 2004). Quercetin is reported to generate apoptosis in cancer cell lines including such human bladder, cervical, ovarian, and breast (Su et al. 2016; Ranganathan et al. 2015). Ellagic acid, another flavonoid observed in honey, generates apoptosis in cancer cells (Ranganathan et al. 2015; Mishra and Vinayak 2014). A mouse study found that Kaempferol had a significant effect on apoptosis in bladder cancer (Umesalma et al. 2015; Dang et al. 2015), colon cancer, ovarian cancer, human cervical cancer, and breast cancer cells (Xie et al. 2013; Lee et al. 2014).

3.5.7 Terpenes

Terpenes are organic and volatile compounds naturally synthesized by honey. Very small amount of terpenes are reported from honey (Kaskoniene and Venskutonis 2010). The characterization of botanical sources of honey has been done by terpenes present in it (Kaskoniene and Venskutonis 2010; Bogdanov et al. 2004). These compounds are aromatic and reported to be active against a wide range of microorganisms such as Gram-negative and Gram-positive bacteria, fungi, and viruses. Different terpenes and their derivatives such as linalool, a-pinene, b-pinene, limonene, camphene, myrtenol, trans-anethol, p-cymene, nerol, and cumene are present in honey (Mato et al. 2003). The flavor, odor, and biomedical properties in honey vary due to the presence of terpenes and their derivatives (Labropoulos and Anestis 2012; Ananias et al. 2013). Norisoprenoids are products of carotenoids (White Jr 1979; Bogdanov 2011b), which influence honey odor (Bogdanov 2011b), and they are known to be anticarcinogenic (Gomes et al. 2010). Terpenes can be identified by gas chromatography quadrupole mass spectrometry which provides qualitative and quantitative data for the identification (Anklam 1998; Cuevas-Glory et al. 2007). These terpenes are found to possess antimicrobial, anti-oxidant, and anti-cancer effects (Manyi-Loh et al. 2011). Several techniques are used for the isolation of terpenes like static headspace extraction, solvent extraction, ultrasound-assisted solvent extraction, etc. (Anklam 1998; Cuevas-Glory et al. 2007; Piasenzotto et al. 2003; Alissandrakis et al. 2003). The oxygenated terpenes can be water-soluble; therefore, heat should not be applied to honey during the isolation technique (Jerkovic et al. 2007). All terpenes are produced from the dimethyl allyl pyrophosphate and its isomer 3-isopentenyl pyro phosphate (Maffei et al. 2011; Dewick 2009). The mostly found terpenes in honey are monoterpenes which are derived from geranyl pyrophosphate (GPP) (Alissandrakis et al. 2007; Jerkovic et al. 2009, 2013).

3.5.8 Pollen

The clearness of honey lies on the level of suspended components like pollens (Busserolles et al. 2002). The pollen and the flower nectar are the key sources of carbohydrate and protein of the honeybees. They also contain fat, vitamins, microelements, etc. (Razquin et al. 2009). Hypersensitive responses from nectar are very uncommon, it could be because of pollen (Petrus et al. 2011). Pollen delivers antibacterial and antimicrobial properties to the honey (Khalil et al. 2011; Beretta et al. 2007). It is easy to describe the environmental conditions and the flora around the beehive using the pollen analysis. The flora of the origin reflects the pollen content (Alvarez-Suarez et al. 2013). Honey can be classified as monofloral or multifloral with the dominating pollen grain arising from one particular plant (Khalil and Sulaiman 2010; Viuda-Martos et al. 2008; Kimmich and Randles 1978). Acid phosphatase can be used as a parameter for honey characterization, and it mainly originates from nectar and pollen (Murtaza et al. 2014). The geographical region from which the honey is collected affects its phenolic, flavonoid concentrations and its pollen distribution (Candiracci et al. 2012; Kasala et al. 2015). The presence of vitamins, iron, other minerals, and immune enhancing properties has shown that honey bee pollen improves egg quantity, general fertility, and fecundity (Ronnekleiv-Kelly et al. 2016).

3.5.9 Minerals

Honey contains minerals which are classified as major and minor elements (35, Bogdanov et al. 2008). The major elements are potassium, chlorine, sulfur, sodium, calcium, phosphorus, magnesium, silicon, iron, zinc, and manganese, and the minor elements are copper, chromium, lithium, nickel, lead, tin, osmium, beryllium, vanadium, zirconium, silver, barium, gallium, bismuth, gold, germanium, and strontium (Solayman et al. 2016; Anderson et al. 1997). The elements like copper and zinc can increase the insulin sensitivity (Sitasawad et al. 2001; Song et al. 2003). These minerals are present in honey in a very low amount (Oh and Yoon 2008; Bogdanov et al. 2008), and a daily consumption of honey may give an adequate concentration of these minerals (Erejuwa et al. 2011). An evidence has shown that after the supplementation of honey, there is an increase in serum concentrations of these minerals (Al-Waili 2003), and these ions also promote the antidiabetic effect of honey (Sitasawad et al. 2001; Oh and Yoon 2008). In light and dark honey, the mineral content varies (Alqarni et al. 2012). Minerals in the soil transported to the flowers and get into honey by the honeydew or nectar (Anklam 1998), and they also come from anthropogenic sources or by beekeeping practices and honey processing methods (Pohl 2009). The mineral content in honey can be analyzed by acid digestion followed by the spectral analysis such as flame atomic absorption (FAAS), graphite furnace atomic absorption (GF-AAS), electro thermal atomic absorption (ET-AAS), inductively coupled plasma optical emission (ICP-OES), and inductively coupled plasma mass spectrometry (ICP-MS) (Pohl et al. 2012). Minerals are indestructible (Damodaran et al. 2010) and play an important role in body function (Pohl et al. 2012).

3.6 Conclusion

In conclusion, honeybee phytochemistry seems to be an interesting field of research with the prospects to explore new environmental relations between plants and bees, new chemical moieties, and new pharmacologically active molecules.