PhD

The present investigation entitled “Exploring the health potential of honey and development of a value added nutraceutical drink” was carried out to analyze the quality of different bee honeys in the raw as well as processed form available in Kerala and to develop a nutraceutical drink utilizing the Apis cerana bee honey, major bee honey in Kerala with an idea of value addition. The major bee honeys included in the study were Apis cerana indica, Apis mellifera, Apis dorsata, Apis florae and Trigona iridipennis. The physicochemical parameters, nutrient analysis and health promoting functions of the honeys were analyzed.
The moisture content of the honeys ranged from 10.03% to 19.79% with lowest being in raw Apis dorsata honey and highest in raw Trigona iridipennis honey. The electrical conductivity of the honeys ranged from 0.26 to 0.26 mS/cm among raw honeys and from 0.13 to 0.34 mS/cm among processed honeys. Significant difference (p < 0.025) was observed in the electrical conductivity of raw honeys. The ash content of the honeys was found to be 0.16% to 1.07% among the raw honeys and from 0.06 to 0.16% among the processed honeys. Significant reduction of ash content was noticed in Apis dorsata honey. The reducing sugars percentage among the raw honeys ranged from 33.03% to 67.6% and from 54.34% to 62.9%. The raw Apis florea honey varied significantly from all the other honeys in the reducing sugars. Significant difference (p < 0.025) was also noted among the processed Apis mellifera and Apis dorsata honeys.
The sucrose content among the honeys varies from 5.31% to 19.73% and significant difference was observed among the raw Apis cerana and Apis dorsata honeys at p < 0.025 level. The fructose glucose ratio among the raw honeys ranged from 1.05 to 1.66 and from 1.15 to 1.71 among the processed honeys. The free acidity of the honeys ranged from 0.15% to 0.68% and all the honeys were significantly different (p < 0.025) in acidity. The pH of the honeys ranged from 3.49 to 4.45 and all the honeys under the study varied significantly (p < 0.025). The specific gravity of the raw honeys ranged from 1.28 to 1.40 which varied significantly at p < 0.025 level, while there was no significant difference among the processed Apis cerana, Apis dorsata and Apis mellifera honeys. The major quality criteria utilized to analyze the extent of processing did to the raw honey was estimated in terms of the amount of hydroxymethyl furfural content and diastase activity. The hydroxymethyl furfural content of the raw honeys ranged from 3.4 to 30.01mg and from 6.36 to 51.87mg among the processed honeys. Significant increase in the HMF content was noticed among the processed honeys. The diastase activity of the raw honeys ranged from 36.7 to 57.5 DN and from 27.32 to 54.26 DN among the processed honeys. Significant difference in the diastase activity among the raw and processed honeys at p < 0.025 level and also between the raw and processed form (at 1%) of each honey was observed. Physico chemical parameters of honeys studied was compared with the cutoff limits as quality criteria set by European Union (EU) council. Moisture and electrical conductivity were within the limits as specified by EU, while slight elevation was noticed in honeys viz., Apis mellifera and Apis florea in their ash content, sucrose content and acidity. Hydroxymethyl furfural content and diastase activity of the honeys were within the levels of EU directive.
The colour intensity of the honeys were determined in terms of the chromatic components and revealed that Apis florea, raw Apis Trigona, processed Apis mellifera, raw and processed Apis dorsata honeys had lower luminance values exhibiting amber colour while all the other honeys had lighter colour showing the prominence of other tones in them. With regards to the ‘a’ and ‘b’ values all the honeys were having reddish tone and yellowish chroma. Visco elastic properties of the honeys depicted that raw and processed Apis cerana, Apis mellifera, Apis dorsata and Trigona had viscous property with high loss modulus (G'') values and Apis florea honey exhibited slight elastic property with high storage modulus (G') value. Apart from the physico chemical characteristics the microbial contamination of the honeys were also analyzed with aim to analyze the quality of the honey. The microbial analysis indicated that none of the honeys analyzed were infested with pathogenic coliforms.
The sensory evaluation of the raw and processed honeys revealed that raw Apis dorsata was highly acceptable (7.35) and processed Apis dorsata was least acceptable (1.05). The most acceptable colour was for raw Apis mellifera honey (6.50) and texture for processed Apis cerana honey (5.95). Significant difference (at 5%) was noted in the sensory parameters among all the honeys analyzed. The free choice profiling technique was utilized to know the distinctive character of each sensory attribute exhibited by the honeys. The presence of amber colour was noted in Apis florea, raw Apis mellifera, raw Trigona and processed Trigona. Fruity aroma was detected in raw and processed Apis cerana, while medicinal aroma was prominent in Apis florea and all other honeys had floral aroma with an exemption to processed Apis dorsata which yielded a fermented aroma.
The nutrients in the honeys were analyzed and the energy content of the honeys ranged from 328 to 353kcal and carbohydrate content from 80.25g to 88g per 100g of the honey sample. The protein content of the honeys was negligible and the major amino acid proline was detected only in raw and processed Apis dorsata (4.5mg each) and Trigona iridipennis (8mg and 3mg) honeys. The vitamin C was found to be negligible in the honeys, while vitamin A and E were not detected. With respect to the mineral content potassium was detected at higher levels among all the honeys, which ranged from 30.5 to 52mg/100g among the raw honeys and from 28 to 47.5mg /100g among the processed honeys. The iron content was noted to be from 0.54 to 1.4mg/100g among the raw honeys and from 0.24 to 1.3mg/100g among the processed honeys, while the calcium, sodium and phosphorous were also recorded to be very less. The trace elements analyzed were zinc (0.04 to 5mg/100g), copper (0.002 to 0.13mg/100g) and manganese (0.001 to 0.35mg/100g) and it was noticed that all the level of three elements were in traces in all the honeys analyzed, but they are involved in umpteen biochemical functions in the body as metalloenzymes. Hence the presence of trace elements even in marginal levels might exert therapeutic properties to the honeys.
The health promoting functions of the honeys were analyzed which includes the phytochemical profiling, antioxidant activity, antidiabetic activity and antimicrobial activity. The phytochemicals analyzed were polyphenols, flavonoids and flavonols. Among the raw honeys polyphenols were high in Apis dorsata (1168mg/kg) and low in Apis mellifera (905.25mg/kg); flavonoids were high in Apis dorsata (545.75mg/kg) and low in Apis cerana (185mg/kg) and flavonols were high in Trigona iridipennis honey (17.6mg/kg) and low in Apis mellifera (4.64mg/kg) and Apis florea (4.6mg/kg) honeys. Significant difference was noticed among all the honeys analyzed with respect to the phytochemicals and significant reduction in the phytochemicals was also observed on processing among all the honeys.
The total antioxidant activity of the honeys was found to be highest in raw and processed Trigona (99.22%, 93.73% at 500µg/ml) honey followed by Apis cerana (97.04% at 500µg/ml) honey among the raw honeys and Apis mellifera (93.4% at 500µg/ml) among the processed honeys respectively, while moderate level of activity was noted in raw and processed Apis dorsata with 73.64% and 64.84% of antioxidant activity at at 500µg/ml. The DPPH radical scavenging activity was found to be highest in raw and processed Trigona honey (97.21%, 92.56% at 500µg/ml) followed by raw Apis cerana (95.55% at 500µg/ml) and processed Apis mellifera (88.18% at 500µg/ml) honeys, whereas comparatively lesser scavenging activity was viewed in processed Apis dorsata honey (48.17% at 500µg/ml). Average scavenging activities were noted in raw Apis dorsata and Apis florea. Significant differences (p < 0.025) in the radical scavenging activity were observed among all the raw honeys analyzed. On contrary to the above discussed antioxidant activities, non linearity was observed among the honeys in the nitric oxide scavenging activity. The highest nitric oxide scavenging activity was observed in raw Apis mellifera (77.19% at 500µg/ml) followed by Apis dorsata (68.22% at 500µg/ml) and Apis florea (65.35% at 500µg/ml) honeys.
The antidiabetic activity determined in terms of alpha amylase inhibition capacity showed highest inhibition in raw and processed Trigona (77.61% and 64.84% at 500µg/ml) honeys followed by raw Apis dorsata (44.34% at 500µg/ml) honey. Average enzyme inhibition was observed among raw Apis mellifera (41.32% at 500µg/ml) and Apis florea (41.30% at 500µg/ml) honeys correspondingly. Higher rate of alpha glucosidase was also observed among the honeys ranged from 76.14% to 80.46% among the raw honeys and from 69.17% to 78.29% among the processed honeys. Significant (at 5%) reduction in the percentage inhibition was noticed in processed honeys. The glycemic index (≤ 67) and glycemic load (≤ 13.54) of the honeys revealed that all the honeys belong to intermediate GI foods category. The antimicrobial activity of the honeys analyzed revealed that raw honeys had higher antimicrobial activity than the processed form with highest in raw Trigona followed by Apis mellifera and Apis cerana honeys.
From the elaborative analysis on the health promoting function of the bee honeys it could be concluded that raw honeys have higher health boosting properties when compared to the processed honeys. The screening index in terms of the therapeutic potencies showed that Trigona iridipennis honey had the highest therapeutic potency followed by Apis mellifera honey, while comparatively moderate potency was observed in Apis dorsata and Apis cerana honeys.
A value added nutraceutical drink was developed utilizing the Apis cerana bee honey, the most abundantly available honey in Kerala. The drink was formulated by working out different proportions of honey in combination with aloe vera gel. The bitterness of the aloe gel was removed by trying out different pre treatment combinations. The physico chemical characteristics of the drink revealed that the drink is mildly acidic in nature with 61% moisture, total soluble solids (35°Brix), acidity (0.34%) and pH (4.88). The total and reducing sugars of the nutraceutical drink were 29.69% and 18.62% respectively. The fructose to glucose ratio of the nutraceutical drink was observed to be 0.99.
The drink was found to have high therapeutic potency with 1060 (mg gallic acid/kg drink) of polyphenols, 60 (mg quercitin/Kg drink) of flavonoids and 5 (mg catechin/Kg drink) of flavonols respectively. Remarkable in vitro total antioxidant capapcity (72.1µgAAE/mg at 500µg/ml), DPPH radical scavenging activity (58.4% at 500µg/ml) and alpha amylase inhibition capacity (43% at 500µg/ml) with a medium glycemic index of 65 was also determined. Even though, the drink exhibited a slight increase in the acidity and TSS on storage the drink was noticed to be free from microbial proliferation and was acceptable till the end of the storage period, indicating its fitness for consumption even after two months of storage. The cost of the drink was found to be Rs 22.00 per 200ml and yield ratio was 1.49.
The clinical efficacy of the drink was determined through a supplementation study which inferred that the platelet count increased significantly (at 5%) in the subjects from 2.56± 0.02 lakh/cumm to 3.05 ± 0.04 lakh/cumm. The supplementation had resulted in improved haemoglobin levels of the respondents from 10.83±0.06 gm% prior the study to 12.01± 0.02gm% at the end of the study. Significant improvement was also recorded in the hematological indices viz., WBC (from 7310± 114.3 to 8330 ± 43.7 cells/cumm), RBC (from 4.16 ± 0.05 to4.48±0.03 millions/ cumm), MCV (88.06 fL to 92.36 fL) and PCV (36.24±0.54% to 39.78± 0.42%) under the study. Encouraging results were also obtained from the total antioxidant capacity of the serum of the subjects under investigation.
Findings of the present study strongly recommend that bee honeys are indeed the elixir of life with admissible physico chemical characteristics and superior health promoting functions. Among the honeys analyzed the raw honeys (Apis cerana, Apis mellifera, Apis dorsata, Apis florea and Trigona iridipennis) were found to be better in terms of quality as well as therapeutic potency when compared with the processed honeys. Among the raw honeys Trigona iridipennis honey was found to the best in medicinal value.
In vitro and in vivo studies prove the efficacy of the developed drink to be a novel option in the market of nutraceuticals with superior health boosting properties and being natural by all means.