Essay: Bael Fruit

Bael Fruit (Aegle marmelos L. Correa) is an indigenous fruit known in India from prehistoric times. The bael fruit is native to india, but most commonly found throughout the Indian peninsula (Rahman and Pravin 20014). Bael also grows in Pakistan, Sri Lanka, Bangladesh, Burma, Thailand and most of the southeastern countries (Rakesh et al., 2005). It is a very hardy subtropical, deciduous tree that can thrive well in different soil-climatic conditions (from swampy to dry soils) and can tolerate alkaline soil. Bael is growing wild in Sub-Himalayan tracts from Jhelum eastwards to West Bengal; as well as in central and south India (Tandon and Gupta 2004). Bael tree is up to 15 m tall with bark, short trunk, thick, soft and spiky branches. The bael fruit has a smooth, woody shell with a gray, green or yellow peel. It takes about 11 months to ripen on the tree and can get in touch with the size of a large grape fruit and some are even larger (Boning (2006). Different parts of plant are used in Unani and Ayurveda medicine for the treatment of different diseases such as dysentery, diarrhea and dyspeptic symptoms (Satyavati et al., 1976; Jauhari et al.,1969). All parts of the tree have medicinal qualities (Chanda et al., 2008). All parts of the tree i.e., stem, bark, leaves, fruits, and roots are found effective as ethno medicines against various human ailments (Badam et al., 2002). There are no standardized names of bael cultivars. They are named after the name of the locality where they are most easily available. Its main cultivated varieties in India are Kagzi Etawah, Kagzi Banarsi, Mirzapuri, Kagzi, Gonda, Narendra Bael-1, Narendra Bael-2, Narendra Bael-5 and Narendra Bael-9.
Table : Scientific classification of Bael.
Kingdom Plantae
Order Sapindales
Family Rutaceae
Genus Aegle Corrêa
Species Aegle Marmelos
Binomial name Aegle marmelos (L.) Corr. Serr.
The ripe fruit of bael is nutritious, sweet aromatic and very pleasant being highly esteemed and eaten by all classes of people (Charoensiddhi and Anuprung 2008). The fruit has excellent odor which is not affected even during processing, thus there is unused potential for processing bael into various products (Singh et al., 2014). The fully mature fruit is not much used in medicines. Half mature fruit are mostly used in medicine (Kumar et al., 2012). The marmelosin content which is found in this fruit is known as “universal remedy of stomach ailments”. The following constituents are reported to be present in this fruit: marmelosin, psoralen, aegelin, scoparone, alloimperatorin, imperatorin, Scopoletin, tannic acid, xanthotoxol, Umbelliferone (Kamalakkannan and Prince 2005).
Table: Nutritional Composition of bael fruit
Nutrient Amount
Moisture (g) 61.0
Protein (g) 1.6
Fat (g) 0.2
Mineral (g) 1.9
Fibre (g) 2.9
Calcium (mg) 80
Phosphorous (mg) 52
Iron (mg) 0.5
Carotene(µg) 55
Thiamine (mg) 0.12
Niacin (mg) 1.0
Vitamin C (mg) 8
Potassium (mg) 610
Copper (mg) 0.20
SOURCE: *Singh et al., (2014)
Patel et al., (2012) reported that Fragment flowers, in cluster of 4 to 7 along little stem lets, have 4 recurred, yellowish inside, fleshy petals green outside, and 50 or more greenish-yellow stamens.
Chattopadhyay (1988) reported that bael is extremely hard tree and grows in all type of soils. It thrives well even in alkaline, Swampy and stony soils having pH range of 5 to 10. Although, for superior growth and yield, well drained, humus soils having pH range from 5.5 to 7.5 is good.
Roy et al., (1979) reported that the three lobed leaves of bael tree are usually used as sacred offerings to “Lord Shiva” according to the Hindu tradition. It has been said that bael tree indicates the presence of underground water. Bael is sub-tropical tree but grows well both in tropical and sub-tropical climate up to an altitude of 1219m. It is medium in size, about 12 to 15 m in height with short trunk, soft, thick, flaking bark. Bael is one of the choicest fruits of arid and semi arid zones due to its drought resistance and tolerate to temperature upto 48°C.
Lambole et al., 2010 reported that in Punjab bael grows up to an altitude of 4,000-ft (1200-m) somewhere the temperature rises to 120°F (48.89°C) in summer and descends to 20°F (-6.67°C) in the winter and propagated droughts occur.
Jauhari et al., (1969) suryed the central and the eastern Utter Pradesh, Western Bihar and selected seven varieties of bael for physicochemical studies. They found that “Kaghzi Etawah” as the best variety having 1893 g weight per fruit and 1582 g pulp per fruit with 0.33% acidity, 36% TSS and 21.7 mg ascorbic acid per 100 g edible pulp.
Results of phytochemical showing of the aqueous extract revealed the presence of saponin, tannins, steroid, terpenoids, lignin and flavonoids. Alcoholic extract showed the availability of alkaloids and devoid of saponin.
Bag et al., (2011) studied the foam stability and foam expansion of the bael fruit pulp foam. Foam were prepared from various pulp concentrations (PC) by adding up different concentration of methyl cellulose (MC) and glycerol monosterate (GMS) at dissimilar whipping time (WT). RSM was used to predict the foam stability and foam expansion. The optimum conditions achieved after the graphical and statistical optimization for highest foam stability and foam expansion was : GMS (3.10 g/100g pulp ), MC (0.32 g/100g pulp), PC(13.2° Bx), and WT (2 min).
Singh et al., (2014) had evaluated the effect of pretreatment on various thermal and physical properties of Bael pulp. The bael fruit pulp was extracted and TSS of the extracted bael fruit pulp was raised to 25°Brix by adding 65°Brix sugar syrup. The pH of pulp was set at 3.0 and 3.5, which was heated at 80-85°C for 15, 20 and 25 minutes and kept at refrigerated conditions at for 80 days. The product was analyzed for pH, Titratable acidity, TSS, thermal properties, colour values and yeast and mold counts during storage. The pH, Titratable acidity, TSS, colour-L*, a*, b*, thermal conductivity and specific heat ranged between 2.6-3.5, 0.15-0.35%, 18-25°Brix, 20.32-56.87, 2.95-20.28, 23.58-64.01, 0.37- 0.76 w/m°C, 1.73-2.50 J/g°C respectively. The microbial load in terms of yeast and mold counts was also under the prescribed limits for 60 days under the refrigerated conditions. Minimum colour change and maximum sensory score was observed at 3 pH and 15 min heating under refrigerated storage. The zero or first order models were well fitted for the responses of the bael pulp (3 pH, 15 min) stored under refrigerated conditions.
Sujatha et al., (2011) conducted pharmacogostical and preliminary phytochemical studies on bael fruit base pulp. Fruit pulp revealed the presence of phenolic compounds, steroids, flavonoids, lignins, terpenoids, saponins, fat and oil, carbohydrates, proteins, amino acids and reducing sugars. These results would be of enormous value in the botanical identification and standardization of drugs in crude form.
Singh et al., (2014) studied the effect of incubation temperature (28.18-61.82°C), incubation time (97.5-652.5 min) and pectinase concentration (0.64-7.36 mg/25 g bael pulp) on juice yield, viscosity and clarity of juice. The recommended enzymatic treatment conditions were incubation time (425 min), incubation temperature (470°C), pectinase concentration (5.0 mg/25 g bael pulp) and the juice yield, viscosity and clarity under these conditions were 84.5%, 1.35 cps and 22.43%, respectively.
Rathod et al., (2014) had optimized that Bael fruit juice (Aegle marmelos correa) and Aonla (Emblica officianalis) were optimized to a blended beverage which was stored for 45 days in PET bottles (200 ml capacity) at refrigerated temperature. Physicochemical and
sensory analysis was evaluated. Marginal changes in total soluble solids, acidity, pH and Ascorbic Acid (vitamin C) were observed. Estimation of Ascorbic Acid content of sample (29.61mg) showed high improvement in nutritional value of Bael juice incorporated with Aonla juice. The acidity increased (0.66-1.11) and pH of the juice decreased progressively during the storage period. The mean overall acceptability scores of more than 8 for juice
samples up to 40% Bael juice incorporation. The sample (40:60 ratio) of (Bael:Aonla) indicated the commercial scope for manufacturing good and nutritious Bael juice blended with Aonla juice. Heat pasteurization by thermal processing i.e., (900°C for 25 sec) was more effective for inactivating the microbial flora. However the shelf life of juice was established within 45 days. The product is recommended for children, youth and elderly
persons to be used within 45 days.
Rajan et al., (2011) had stated that bael fruit pulp has been used as a remedy for gastrointestinal infections of human. This study reveals the antioxidant potentials of bael fruit pulp extracts. Standard methods were adopted to screen antioxidant and phytochemical nature of bael fruit pulp. Results of Phytochemical screening of the aqueous extract revealed the presence of saponins, lignin, tannins, steroid, terpenoids, flavonoids. Alcoholic extract showed the availability of alkaloids and devoid of saponin. In vitro antioxidant activity of the plant extract revealed that both the extracts showed good antioxidant power with IC50 value ranges for 37.11±3.50 to 158.99±59.46 µg/ml for aqueous extract and 35.02±8.10 to 283.06 ± 135.80µg/ml for alcoholic extract.
V. R. Sagar and Rajesh Kumar (2014) had evaluated that Dehydration of bael pulp in to powder form is a challenging operation, mainly due to the sticky issue of bael
pulp and caking of powder during handling and storage. To overcome on this problem tricalcium phosphate and maltodextrin MD (drying aid), TCP (anti caking agent) were
added to the bael pulp at four levels along with control and dried in a mechanical drier into thin layer at 58±2 °C for 12 h, to obtain a moisture content of 4—5 % in dehydrated pulp. The dehydrated bael pulp was grounded in a laboratory powder mill and sieve with 30 mesh sieve. The powder was packed in 150gauge PP, 400gauge LDPE and
200gauge HDPE pouches and was stored at low temperature (7 °C) and ambient condition (18—35 °C) up to 6 months for storage study. The powder was evaluated for its quality
characteristics in respect of acidity, sugars, antioxidant, phenol, ascorbic acid, non- enzymatic browning (NEB) before packaging and during storage. The amount of MD and TCP required to reduce powder stickiness and caking were optimized on the powder properties. The amount of MD (0.25 kg per kg dry bael solids) and TCP (0.15 kg per kg
dry bael solids) with the values of degree of caking (19.24 %) and stickiness point temperature (45.4 °C) were found to be optimum for reducing the powder stickiness,
caking and nutritional parameters. The adsorption isotherm of bael powder was found to be type-II sigmoid and 200 g HDPE as packaging material followed by storage at low
temperature were selected as best process.
Bassiounny et al., (1990), Mansour and Khalil (2000), Reddy et al.,(2005), Roy et al., (2010) reported the importance of natural antioxidants for use as food additives or nutritional supplements has already been established .
Sachindra et al., (2010) reported that with the focus is being shifting towards finding alternatives for synthetic food ingredients, natural substances having antioxidant properties need to be further explored. Antioxidants or ingredients having antioxidant properties are used extensively for improvement of food stability.
Rana and Jain (1997) evaluated the anti fungal activity of essential oil isolated from leaves of the Aegle marmelos with spore germination assay and the oil established variable efficiency against different fungal isolations.
(Shoba and Thomas 2001) reported the efficacy of methanol extract of bael in rodents against castor oil induced diarrhoea with reduction of both the induction time of diarrhoea and total weight of the feces.
Shoba and Thomas (2001), Dhuley (2003) reported that Aegle Marmelos have anti-diarrheal properties, and Lampronti et al., (2003) reported that bael have anti-proliferative properties and Arulet et al., (1997), reported that the bael fruit have anti-inflammatory and Upadhyay et al., (2004), Kesari et al., 2006, Narender et al., (2007) reported that the bael have antipyretic and hypoglycemic properties and Sabu and Kuttan (2004) reported that the bael have anti-oxidant properties.
Various proved therapeutic values of Aegle marmelos:
1. Anti-diabetic Activity: Aqueous extract of Bael fruit leaves, was evaluated for antioxidant and hypoglycemic effect by Upadhya S et al., (2004) by using alloxan induced diabetes in male albino rats and proposed AML may be useful in the long-standing management of diabetes. Similarly, Anti-hyperlipidaemic activity of aqueous extract of Bael fruits was demonstrated by P.S. Marinzene et al., (2005), using the streptozotocin IJCPR February-April 2011; 2(1) 14 induced diabetic wistar rats. Sunderam et al., (2009) worked on alcoholic extract of Bael fruit, Momordica Charantia and Eugenia Jambolana separately; against Streptozotocine induced diabetic rats and confirmed their protective activity against laboratory induced cell necrosis, where Kuttan & Sabu ( 2004) studied on leaf extract of Bael fruit on Alloxan induced diabetes and reported that used extract was enough capable to reduce oxidative stress by scavenging lipid peroxidation and enhancing certain anti-oxidant levels which causes lowering of elevated blood glucose level. Beside of all above cited work, Hema & Lalithakumari (1999) had presented tremendous results of Aegle Marmelos and documented its hypoglycemic action along with other pharmacological actions on molecular level.
2. Hepatoprotective activity: Singanan et al., (2007) worked on Bael fruit leaf extract on alcohol induced liver injury in albino rats and presented data of excellent hepatoprotective effects. Similarly, Ramnik S (2008) also demonstrated that aqueous extract of bael fruit pulp and seeds are effective in the treatment and prevention of CCI4 induced hepatic toxicity.
3. Antimicrobial Activity: Maheshwari et al., (2009) studied on Ethanolic extract of dried fruit pulp of Aegle Marmelos against various intestinal pathogens i.e. Shigella boydii, S. sonnei & S. Flexneri proposed that certain phytochemicals including Phenols, Tannins and Flavonoids were effective against all. It was also confirmed by Kaur et al., (2009) by getting treat E.Coli with Aegle Marmelos fruit extract. In consonance, Citarasu et al., (2003) also experimented Aegle Marmelos on certain pathogenic bacteria like Salmonella typhi, Pseudomonas aeruginosa, Aeromonas hydrophyla & Vibrio sp., and concluded its positive bactericidal effects.
4. Analgesic anti-inflammatory & antipyretic Activity: Arul et al., (2005) presented anti-inflammatory, antipyretic & analgesic properties of serial extract of leaves of Aegle Marmelos, and presented that most of the extract caused a significant inhibition of the carrageen an-induced paw edema and cotton-pellet granuloma in rats. The extracts also produced marked analgesic activity by reduction the early and late phases of paw licking in mice. A significant reduction in hyperpyrexia in rats was also produced by the most of the extracts. Similarly, Ghangale G. R (2008) also evaluated aqueous extract of Aegle marmelos for anti-inflammatory activity by using rat paw edema model and proposed that Aegle marmelos posses anti-inflammatory activity. Shankharananth V ( 2007), demonstrated that methanolic extract of leaves of Aegle marmelos at a dose level of 200 IJCPR February-April 2011; 2(1) 15 and 300 mg/ kg show significant analgesic activity on acetic acid induced writhing and tail flick test in mice.
5. Antifungal Activity: Patil R. H (2009) reported the antifungal activity of Ethanolic extract
of the Aegle marmelos leaves including antidiarrhoeal, and antimicrobial, activities. Rana B. K. (1997) evaluated anti fungal activity of essential oils isolated from the leaves of Bael using spore germination assay. The oil exhibited variable efficacy against different fungal isolates and 100% inhibition of spore germination of all the fungi tested was observed at 500ppm.They proposed that essential oil from bael leaves may interfere with the Ca2+-dip colonic acid metabolism pathway and possibly inhibit the spore formation. Pitre and Srivastava (1987) demonstrate the anti fungal activity of Ethanolic root extract against Aspergillus fumiganus and Trichphyton mentagrophytes.
6. Anticancer Activity: Leticia V and Costa L. (2005) evaluated the anticancer potential of folk medicine used in Bangladeshi and used extracts of Aegle marmelos for cytotoxic action using brine shrimp lethality assay; sea urchin eggs assay, and MTT assay using tumor cell lines. The extract of Aegle marmelos was found to exhibited toxicity on all used assays. Similarly, Gagetia G.C. et al., (2005) reported the anticancer effect of hydro alcoholic extract of bael leaves in the animal model of Ehrlich as cites carcinoma and proposed that induction of apoptosis may be due the presence of skimmianine in extract.
7. Radioprotective Activity: Radioprotective effect of Aegle marmelos extract was studied by Jagetia G.C and Venkatesh P (2005) by exposing to different doses of gamma-radiation in mice and found that oral administration of extract resulted in an increase in radiation tolerance by 1.6 Gy. Again, Jagetia G.C and coworkers (2006) studied effects of plant extract on the peripheral blood and small intestine of Swiss albino mice. They exposed the animals to gamma radiation and data were collected against radiation-induced changes in the peripheral blood, spleen colony forming units, and intestinal mucosa, reported that Aegle marmelos extract significantly reduces the deleterious effect of radiation in intestine and bone marrow of mouse.
8. Antispermatogenic Activity: Pramanik et al., (1999) reported Antispermatogenic activity of Ethanolic extract of Aegle marmelos leaves in rats. Again, the same workers, including Bhattacharya D. (2002) presented data of anti motility of rat sperms through In Vitro study.
Similarly, Sharma R. C et al., (2009) studied the effect of ethanol extracts of leaves of A. marmelos for their in vitro effect on sperm motility and was suggested that the extracts had a considerable effect on the motility of sperm. It was also proposed that an increase in concentration of the extracts decreased the motility of sperms. IJCPR February-April 2011; 2(1) 16
9. Antiulcer Activity: Goel R.K (1997) reported that oral; administration of pyranocoumarin isolated from the seeds of Aegle marmelos Correa, showed significant protection against pylorus-ligated and aspirin-induced gastric ulcers in rats and cold restraint stress-induced gastric ulcers in rats and guinea pigs. Dhuley J. N (2007) reported that pretreatment of rats with unripe bael fruit extract produce a significant inhibition of absolute ethanol induced gastric mucosal damage.
10. Anti thyroid Activity: Panda S, and Kar A. (2006), isolated, Scopoletin (7-hydroxy-6- methoxy coumarin) from Aegle marmelos leaves and evaluate for its potential to control hyperthyroidism. It was observed that Scopoletin (at 1.00 mg / kg, p.o. for 7 days) to levothyroxine treated animals, decreased serum thyroid hormones level. It was also proved that the Scopoletin have superior therapeutic activity than the standard anti-thyroid drug, propylthiouracil.
11. Toxicity Studies: Total alcoholic, total aqueous, whole aqueous and methanolic extracts were collected from the leaves of A. marmelos by the Veerappan A et al., ( 2007) and studied in experimental rats for their toxicity. No histopathological changes were found when extracts of A. marmelos were administered intraperitoneally for 14 days successively at the dose of 50 mg/kg body wt. The collected data demonstrate that the extracts of the leaves of A. marmelos have a high margin of drug safety.
Ohmic heating
Ohmic heating (also called Joule heating, electrical resistance heating, direct electrical resistance heating, electro heating or electro conductive heating) is defined as a process where electric current is passed through food, resulting in a temperature rise in the product due to conversion of electrical energy into heat. Ohmic heating is a thermal processing method in which an alternating electrical current is passed through food products to generate heat internally (Jha et al 2011;Shirsat et al., 2004). Basically heat is internally generated due to electrical resistance (De Alwis, et al., 1990). The advantages of ohmic heating include uniform heating of food products and a very high-temperature-short-time process. Therefore, a high-quality product with minimal structural, nutritional, or sensorial changes can be manufactured in a short operating time. Ohmic heating is distinguished from other electrical heating methods by, the presence of electrodes contacting the foods (in microwave and inductive heating electrodes are absent), the frequency applied (unrestricted, except for the specially assigned radio or microwave frequency range) and waveform (also unrestricted, although typically sinusoidal).
Ohmic heating applications
Recent advances in ohmic heating technology have provided processing alternatives with enhanced temperature uniformity. Ohmic heating is the internal generation of thermal energy by passage of an electric current. Electrical energy dissipated within the materials as heat results in remarkable uniform temperature distribution and high energy conversion efficiency (Salengke, 2000; Jun and Sastry, 2005). Electric field strength and electrical conductivities of materials are key factors governing heating rate of the liquid—particle mixtures. Non uniform heating can be reduced by increasing electrolytic contents in food particles by additional pretreatment such as soaking or blanching of particles in salt solution (Sarang et al., 2007).
Assiry, et al., (2003), worked on degradation kinetics of ascorbic acid during ohmic heating with stainless steel electrodes. The results proposed that degradation of ascorbic acid during ohmic heating using stainless steel electrodes can be described by a first order model. The destruction rate during conventional heating is different than that during ohmic heating with the latter not being described by the Arrhenius relation. Electrolysis and electrode corrosion reactions influence the degradation rate. In particular, the formation of oxides appears to consume electrogenerated oxygen making it unavailable for ascorbic acid oxidation.
Castro, et al., (2004), went out with a study in which they compared the enzyme inactivation kinetics under ohmic and conventional heating. The veteran enzymes were polyphenoloxidase, lipoxygenase, pectinase, alkaline phosphatase, and galactosidase, and the inactivation assays were performed under conventional and ohmic heating conditions. The presence of an electric field does not cause an enhanced inactivation to alkaline phosphatase, pectinase, and galactosidase. However, lipoxygenase and polyphenoloxidase kinetics were significantly affected by the electric field, reducing the time needed for inactivation.
Liezerson and Shimoni (2005), studied the effect on stability and sensory shelf life of orange juice pasteurized by continuous ohmic heating. They found that the shelf life of ohmic-heated orange juice was determined according to vitamin C content, which was similar to that of pasteurized juice and was 79 days. However, the sensory shelf life of ohmic-heated orange juice was prolonged and may influence the type of thermal treatment applied in the industry.
Darra, et al., (2013), carried out a study on the effect of pulsed ohmic heating on extraction of polyphenols and elucidated that temperature has a positive influence on the polyphenol content.
Yildiz, et al., (2008), determined changes in β-carotene, chlorophyll and colour of spinach puree during ohmic heating. They observed that ohmic heating in the range of 10—40 V/cm voltage gradient could be applied to puree samples as an alternative heating method. They also resulted that spinach puree was heated four times faster to the same temperature ohmically than water heating.
Darvishi, et al., (2011), studied the effect of ohmic processing and temperature dependent electrical conductivities of lemon juice. They resulted that electrical conductivity increased linearly with increasing of temperature. The electrical conductivity of lemon juice is strongly dependent on temperature. Ohmic heating times and performance coefficients are dependent on the voltage gradient used. As the voltage gradient increased, time and performance coefficient decreased.
Choi, et al., (2011), conducted a research on a microwave and ohmic combination heater for uniform heating of liquid—article food mixtures. Under tested conditions, they observed that a temperature difference between solid and liquid for individual heating modes, either microwave or ohmic heating, ranging from 11.2 to 18.9°C. Combination heating was able to minimize the temperature difference to less than 2°C.
Darvishi et al., 2013 conducted a research on ohmic heating of pomegranate juice and investigated the effects on electrical conductivity, heating rate, system performance and pH. They concluded that as the voltage gradient increased, time, system performance and pH decreased. The electrical conductivity of the sample increased with temperature rise (20—850C). The range of electrical conductivity and system performance coefficients during ohmic heating were 0.209—1.013 (S/m) &0.764—0.939 respectively.