8. Demand & supply of areca nut in Inda: An analysis

 

As per the nationally representative cross-sectional study conducted in 2016-17 by Tata Institute of Social Science (TISS), Mumbai with support from Ministry of Health and Family welfare, Govt. of India, about 23.9% of the adult population consume areca nut. This translates into approximately 22.38 crore people consuming areca nut in one or the other form in 2016-17. Majority users (13.29 crore) consumed areca nut with tobacco. As per the official documents of TISS Mumbai, the survey was conducted in all 29 states and three union territories (UTs) of India. The study involved the survey of 74,037 adults aged 15 and above. A multistage sampling design separately for rural and urban areas was adopted. The overall response rate was 92.9%. The sampling was done independently in each state/Union Territories, and it was done independently for urban and rural areas.

Let us try to apply the similar calculation to the year 2020. The total population of India was 138.88 crores in 2020. In this, the adult (between 15-65 years of age) population was 94.02 crores. As per the TISS survey data, 22.47 crores (23.9% adult population) must have consumed the areca nut in one or the other form. Out of which, 13.34 crores were the habitual areca nut consumers with Chewable tobacco. Rest (9.12 crores) consumed area nut vocationally.

Discussions with Gutkha/tobacco wholesale traders in Hubli, Karnataka and retailers elsewhere, it was evident that those addicted to chewable tobacco (Smokeless tobacco) consume Gutkha, Mawa, or Paan with tobacco, a minimum of 10 times a day. Each time, about 2.5 gram of areca nut is consumed which translates into 25 grams per day. That amounts to 9.125 Kg of areca nut per year. If we apply this calculation to 13.34 crore individuals who consume areca nut with chewable tobacco, the amount of areca nut consumed would be 12,17,275 Tonnes per annum. Apart from this about 9.12 crore adults consume areca nut in the form of Paan (Betel quid). If we assume, one Paan is consumed per day by them, the total areca nut consumption would be 83,220 Tonnes per annum. Thus, the total areca nut consumption by Indian population in 2020 was 13,00,495 Tonnes.

As per Food and Agriculture Organization of the United Nations (FAO) data released in March 2022, the domestic production of India was 13,82,000 Tonnes in 2020. That shows, there was a surplus of 81,505 Tonnes of areca nut in India in 2020. Perhaps, this was exported to the countries having a sizable areca nut consuming population such as Pakistan, Nepal and Gulf nations. Several records shows that India is the sole manufacturer of Gutka in the world and Gutka is highly popular in those nations.

Most recent data indicates that the Chewable tobacco (smokeless tobacco) users are much more than the 2016-17 estimate (TISS study). As per the recent Lancet report, about 19.94 crore adults chew areca nut with tobacco in India. If we consider this data, India would have consumed a whooping 18,19,525 Tonnes in 2022.  India’s domestic production was 13,82,000 Tonnes in 2020. If we assume 15% year-on-year growth in the domestic production, the areca nut production in 2022 would have reached 18,27,000 Tonnes. The actual production figures are yet to be released by Directorate of Areca nut and Spices Development, Calicut and Food and Agriculture Organization of the United Nations (FAO). 

References:

1.    Singh P.K et al. (2021). Areca nut consumption with and without tobacco among the adult population: a nationally representative study from India. BMJ Open; 11: e043987. doi:10.1136/bmjopen-2020-043987

2.     Arakeri et al. (2023). Unsuccessful ban on gutkha and need for tobacco control in India. The Lancet, Vol 401, pp 1154.

3.      Food and Agriculture Organization of the United Nations data released officially in March 2022.

4.       Directorate of Areca nut and Spices Development, Calicut report published in June 2021.

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5. Phenolic compounds present in Areca nut: Part – III

 

Couple of research groups have tried to identify the prominent phenolic compounds present in the areca nut. Considering the fact that most of the phenolic compounds present in areca nut are structurally similar to each other and exhibit similar physico-chemical properties, identifying and quantifying them is not easy. It requires very advanced instruments, expensive reagents and expertise. Hence, the number of reports on this matter is very limited.

First authentic report on the phenolic compounds present in areca nut was published by Govindarajan & Mathew (1963). They were working in Central Food Technology Research Institute (CFTRI) Mysore, and they tried to identify prominent phenolic compounds present in Chali (White supari). They had identified Catechin, Epicatechin and Leucocyanidins, using a very rudimentary “Paper chromatography method”. In 2013, Chavan & Singhal from “Institute of Chemical Technology” Mumbai, confirmed the presence of catechin and epicatechin in Chali (White supari) using advanced Liquid Chromatography- Mass spectroscopy (LC-MS) method.

In China, Zhang et al. (2014) had used most advanced High Performance Liquid Chromatography - Mass Spectroscopy (HPLC-MS) to identify some of the prominent phenolic compounds present in the areca nuts of 5 month's maturity. They had collected the areca nut sample from Hainan Province of China. They have reported the presence of Epicatechin and Syringic acid in the areca nuts of 5 month's maturity.

One more recent report on the prominent phenolic compounds present in areca nut came from Indonesia. Sari et al., (2020) had tried to identify and quantify the prominent phenolic compounds present in unripe (green) areca nuts (6-7 months’ maturity) collected from West Kalimantan & West Papua and ripened areca nuts (perhaps 9-10 months’ maturity), collected from Banda Aceh & North Sumatra, Indonesia. They had used an advanced LC-MS analysis to quantify those phenolic compounds. They have reported the presence of Catechin & Epicatechin in all the four areca nut samples. In areca nut sample collected from West Papua (6-7 months’ maturity), Sinapic acid, quercetin and resveratrol were also reported. However, they were absent in the ripened areca nut samples. Their results are presented below.

Song et al. (2022) have identified and quantified the prominent phenolic compounds present in the areca seed (after dehusking ) of the areca nuts of 5 month's maturity. They had chosen the areca nut samples from Hainan Province of China.  They had used a most advanced UHPLC–MS/MS to identify and quantify the phenolic compounds. They too have reported the presence of large amount of Catechin and Epicatechin, which is in concurrence with the results of Zhang et al. (2014). Furthermore, they have reported the presence of a significant amount of Procyanidins, which was not reported by Zhang et al. (2014). Some major compounds reported by them are listed below.

Our recent study of unripe green areca nut (6-7 months’ maturity) collected from Belur, Sagar Taluk, Shivamogga district using a most advanced UHPLC-MS/MS confirmed the presence of large number of flavonoids. This study was conducted in 2022 in our lab at NITK Surathkal, Karnataka, India. Altogether 61 compounds belong to phenolic acids, flavonoids, proanthocyanidins, alkaloids, lignans, xanthones, Sesquiterpenes classes were identified. Arecatannin B1, Catechin, Propelargonidin, Procyanidin B2, 5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone, Coniferyl alcohol and Nubigenol were the prominent compounds found in areca nut of 6-7 month's maturity. Isorhamnetin, Phloretin, Isoferulic acid, Hydroxybenzoic acids and syringic acid commonly found in Chinese and Indonesian areca nuts were also identified.

References

1.   Govindarajan & Mathew (1963). Polyphenolic substances of arecanut-I. Chromatographic analysis of fresh mature nut. Phytochemistry. Vol. 2. pp. 321t o 326

2.   Chavan & Singhal (2013). Separation of polyphenols and arecoline from areca nut (Areca catechu L.) by solvent extraction, its antioxidant activity, and identification of polyphenols. Journal of Science of Food & Agriculture.  Vol. 93(10), pp. 2580–2589.

3.     Zhang et al. (2014). Optimization of extraction conditions of areca seed polyphenols and evaluation of their antioxidant activities. Molecules. Vol. 19(10), pp. 16416–27

4.   Sari et al., (2020). Distinct phenolic, alkaloid and antioxidant profile in betel quids from four regions of Indonesia, Scientific Reports, Vol. 10:16254

5.  Song et al., (2022). UHPLC-MS/MS identification, quantification of flavonoid compounds from Areca catechu L. extracts and in vitro evaluation of antioxidant and key enzyme inhibition properties involved in hyperglycemia and hypertension. Industrial Crops & Products. Vol. 189, pp. 115787.

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4. Phenolic compounds present in Areca nut (Karnataka, India): Part – II

A comprehensive study on the Total Phenolic Compounds” Present in the unripe (Green) areca nuts of 6-7 month’s maturity was carried out in my lab by my team in NITK Surathkal. Generally, the harvesting season for green nuts starts in September and continues up to December for making Red Supari (Kempadike) in Karnataka State. The fresh nuts of 6-7 months’ maturity harvested by the farmers for making “Red Supari” (kempadike) were collected from various districts of Karnataka in Dec 2021 & Nov 2022. The locations were chosen so that most of the prominent, traditional Red Supari producing Taluks were covered in this study. The goal was to study the effect of geographical locations on the chemical constituents of the areca nut. The sample locations are pictorial represented below.

The total phenolic content of the fresh areca nut samples was determined immediately brought to the lab under frozen state and the chemical constituents were determined the next day.

The data is presented below.

Lot of variations in the phenolic content was noticed among the samples. The areca nuts cultivated in the relatively dry regions of Shivamogga, Davanagere, Chickmagalur and Haveri districts had higher phenolics compared to other regions.

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3. Phenolic compounds present in Areca nut : Part - I

 

Areca nut contains a large number of phenolic compounds in substantial quantity. Flavonoids (flavones, flavanones, flavanols, flavonols), phenolic acids and polyphenols (procyanidins, areca tannins etc.) are some of the important classes of phenolic compounds found in areca nuts. These compounds are responsible for the dark brownish color in the boiled nuts (Red supari). They impart astringent taste, and they turn red in the presence of lime. Most of the perceived therapeutic properties of areca nut are attributed to these flavonoids, phenolic acids and polyphenols. Almost all of them are highly potent antioxidants. A brief account of proven health benefits of some of the prominent phenolic compounds present in areca nut shall be posted in subsequent Blogs.

Very few reports are available on the systematic study of total phenolic compounds present in the areca nuts at its developmental stages. A brief account of those reports is presented below.

Thailand

Total phenolic content of areca nuts cultivated in Nakhon-Pathom province of Thailand was estimated by Wetwitayaklung et al., (2006).  They have used a standard method to extract and analyze the phenolic content of areca nuts of maturity 1 month to 8 months. They have reported that the total phenolics is in the range of 8 mg/g (by weight on dry basis) in the 1-month-old nut, reaches 10.5 mg/g at the 4th month and reaches 7 mg/g in the 8th month areca nut. The results of their study are presented below. 

Indonesia

One more recent study on the estimation of chemical constituents of areca nuts was reported from Indonesia. Sari et al., (2020) had studied the total phenolic content of unripe (green) areca nuts (6-7 months’ maturity) collected from West Kalimantan and West Papua and ripened areca nuts (perhaps 9-10 months’ maturity), collected from Banda Aceh & North Sumatra, Indonesia. The phenolic content was in the range of 10.88 mg/g to 21.67 mg/g on dry weight basis. The unripe (green) nut collected from West Papua province of Indonesia had the highest phenolic content 21.67mg/g on dry basis, whereas the unripe (green) nuts from West Kalimantan had only 10.8 mg/g of Phenolic compounds. The mature areca fruits from North Sumatra & Banda Aceh had phenolic content of 11.1 mg/g & 12.2 mg/g respectively.

China

A recent study on the total phenolic present in the areca nuts of 5 months maturity has been reported by Song et al., (2022). They had chosen the areca nut samples from Hainan Province of China and they analysed the phenolic content of the seed after separating the husk. They reported the total phenolic content of 36.3 mg/g on dry weight basis. In another study, Wang et al., (2023) had analysed the total phenolic content of areca nut (with husk) of 5 months maturity, collected from 11 prominent areca growing regions of Hainan Province of China. They had used High Performance Liquid Chromatography (HPLC) method to determine the phenolic content. They have reported an average value of 36 mg/g (on dry weight basis). As they had estimated the Phenolic content of areca nut along with the husk, the values seem to be highly inflated.

From the aforesaid literatures, it is clear that there is a great variability in their concentrations in areca nuts cultivated in different regions of the world. The values varied from 6.98 mg/g (8-month sample from Thailand) to 36.3 mg/g (5-month sample from China). The unripe (green) areca nuts of 4 to 5 months maturity have the highest concentration of Phenolic compounds. Interestingly, the areca nut of 4-5 months maturity is harvested and processed to make flavoured Bing lang in China (Refer my Blog No. 6 & 7 under the label “Global areca nut production”).   

References:

1.     1.  Wetwitayaklung et al., (2006). The study of antioxidant capacity in various parts of Areca catechu L. Naresuan University Journal, Vol. 14 (1), pp. 1-14.

2.    2. Sari et al., (2020). Distinct phenolic, alkaloid and antioxidant profile in betel quids from four regions of Indonesia, Scientific Reports, Vol. 10:16254

3.    3. Song et al., (2022). UHPLC-MS/MS identification, quantification of flavonoid compounds from Areca catechu L. extracts and in vitro evaluation of antioxidant and key enzyme inhibition properties involved in hyperglycemia and hypertension. Industrial Crops & Products. Vol. 189, pp. 115787.

4.   4.Wang et al., (2023). Evaluation of Areca Quality Based on Principal Component and Hierarchical Cluster Analyses in Hainan, China. HORTSCIENCE, Vol. 58(6), pp. 699–703.

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2. Major constituents of Areca nut (Supari)

The major constituents of the areca nut are carbohydrates, lipids, proteins, crude fiber, phenolic compounds (flavonoids, phenolic acids and polyphenols), alkaloids and mineral matter. Jayalakshmi & Mathew (1982) have reported that the unripe areca nut of 6-7 months’ maturity will generally have a moisture content in the range of 69.4–74.1% (by weight) whereas the ripe fruit will have moisture content in the range of 38.9–56.7 %. The moisture content will vary depending upon the variety, agroclimatic conditions and the agriculture practices.

The major chemical of unripe green (6-7 months’ maturity) and ripe areca nuts are given below on dry weight basis except for moisture (Adapted from Jayalakshmi & Mathew (1982)). Rudimentary analytical techniques and instruments available at that time were utilized to estimate the components. Nevertheless, the following Table gives the rough estimation of major components. 

As per the report of Mathew et al., (1964) from CFTRI Mysore, who had studied the composition of areca nuts harvested at 2 months, 4-5 months, 6-7 months and 9 months’ maturity collected from Kyatsandra, Mysore, Thirthahalli and Vittal in Karnataka state and Pudupady in Kerala, the lipid (oil) content of the areca nut increased from a low, 1-4 %, in the tender stages to a high, 10-15 %, in the ripe stage. Similarly, the polysaccharide (starch and cellulose) content also starts with a low value at the tender stage and increases progressively until at ripe stage. Crude fibre (cellulose and hemicellulose) starts with a very low value (1-2 %) and with maturity and ripening fibre will be formed continuously and the rate of formation increases until the ripe areca nut showed a value of about 15 %. Rapid protein accumulation happens till the fruits are 3 months old and thereafter the value remained more or less constant. Phenolic substances start with a high value in the early stage and progressively decrease during the developmental stage and reaches the lowest value in the fully ripened fruit. The considerable increase in the hardness of the nut coincides with drop in moisture content and build-up of polysaccharides and crude fibre. Lignification (formation of lignin) and high degree of polyphenol polymerization occur in matured fruit, contributing to the larger insoluble residue and increased hardness of the nut. While the trend in changes of physical and chemical properties with maturity for the samples from different regions was the same, individual variations in relative proportion of constituents were significant.

The study by Jayalakshmi & Mathew (1982) and Mathew et al. (1964) clearly demonstrates that the protein content, lipid content and crude fiber content will be highest in the mature fruit (9-10 months maturity) which is used for making Chali (White supari) and Niradike (Doma, fermented Areca nut). Water content in the areca nut keeps decreasing during the developmental stage and reaches the minimum value in the matured fruit compared to its early stages.

Other major constituents such as Phenolic compounds and alkaloids shall be discussed in my subsequent Blogs.

Reference:

1.      Jayalakshmi A, Mathew AG (1982) Chemical composition and processing. In: Bavappa KVA, Nair MK, Kumar TP (eds) The areca nut palm. Central Plantation Corps Research Institute, Kerala, pp 225–244.

2.      Mathew A.G, Venkataramu S.D, Govindarajan V.S (1964). Studies on Arecanut: Part I - Changes in Chemical Composition & Physical Characteristics of Nuts with Maturity. Indian Journal of Technology, Vol. 2, No.3, pp. 90-96.

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