Habitat and ecology
editAs a xerophytic (drought-resistant) species, carob is well adapted to the ecological conditions of the Mediterranean region with 250 to 500 mm of rainfall per year.[1]. Carob trees can survive long drought periods but to grow fruit they need 500 to 550 mm rainfall per year [1]. Trees prefer well-drained sandy loams and are intolerant of waterlogging, but the deep root systems can adapt to a wide variety of soil conditions and are fairly salt-tolerant (up to 3% NaCl in soil) [1]. After irrigation with saline water in summer Carob trees could possibly also recover during rainfalls in winter [2]. In some experiments young carob trees could uphold basical physiological functions at 40 mmol NaCl/L [2]
Not all legume species can develop a symbiosis with Rhizobia to use atmospheric Nitrogen. For Carob it remains unclear if it has this ability: Some findings suggest that it is not able to form nodules with Rhizobia [1] while in an other study trees have been found with nodules containing bacteria believed to be from the Rhizobium genus [1]. However measuring the 15N-signal in plant tissue did not support that carob trees in the field can use atmospheric nitrogen.[3] Rueeggjo (talk) 21:47, 21 November 2014 (UTC)
Uses
editThe carob pod consists of two main parts which have very different composition and are seprarately used to produce different goods: The pulp accounts for 90% and the seeds for 10% of the pod weight [1][4]. (Table XY gives an overview of the main products from carob pulp and seeds. Tabelle)
Composition and use of the pulp
editThe pulp contains about 48 - 56% of sugars and 18% of cellulose and hemicellulose [1]. There are some differences in sugar contents between wild and cultivated types: Sucrose = 531g ± 93 g/kg dry weight for cultivated varieties and 437 ± 77 g/kg in wild type varieties. Fructose and glucose levels do not differ between cultivated and wild type carob. [5] Carob pulp is sold as flour or chunks [4]. It can be also consumed directly from the dried (and sometimes roasted) pod. Carob is mildly sweet and is used in powdered, chip, or syrup form as an ingredient in cakes and cookies. From the pulp substitutes for cocoa can be produced [4]. Chocolate contains theobromine, which is poisonous to some mammals, but carob does not, and is used to make chocolate-flavored treats for dogs [6].
Composition and use of the seeds
editThe production of Locust Bean Gum (LGB) a thickening agent used in food industry is the economically most important use of the carob seeds (and of the carob as a whole) today. It is produced from the endosperm which accounts for 42 - 46% of the seed and is rich in galactomannans (88% of endosperm dry mass). For 1 kg LBG 3kg of kernels are needed which come from approximately 30 kg carob tree fruit. Galactomannans are hydrophile and swell in water. LGB is used as a thickening agent, stabilizer, gelling agent or as a substitute for gluten in low-calory-products. If galactomannans are mixed with other gelling substances like carrageenan they can be used to thicken food. This is used extensively in canned food for animals to get the jellied texture.[4]
The embryo (20-25% of the seeds weight) is rich in proteins (50%) and its flour can be used in human and animal nutrition [4][1]. The testa (30-33% of the seeds weight) is the seed coat and consists of cellulose, lignin and tannin [4].
Animal feeding
editTraditionally the pulp for animal feeding was the most important use of carob fruits [4]. In the Iberian Peninsula, carob pods were used mainly as animal fodder, especially to feed donkeys. Carob pod meal is used as an energy-rich and palatable feed for livestock, particularly for ruminants, though its high tannin content may limit its use[7].
Traditional uses
editBeside the traditional use as livestock feeding there are various traditions in different countries for using the carob pods:
...existing article
delete: Carob pods were an important source of sugar before sugarcane and sugar beets became widely available.[citation needed]
Ornamental use of the carob tree
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Cultivation
editHarvest and post-harvest treatment
editThe most labour intensive part of carob cultivation is harvesting which is often done by knocking the fruit down with a long stick and gathering them together with the help of lied-out nets. This is a difficult task because at the same time the trees are flowering and care has to be taken not to damage the flowers. Research to get the fruit to ripen more uniformely or also for cultivars which can be mechanically harvested (by shaking) is recommended in the literature.[1]
After harvest carob pods have a moisture content of 10-20% and should be dried down to a moisture content of 8% so the pods don't rot. Further processing is done to separate kernels (seeds) from the pulp. This process is called kibbling and results in pieces of carob pods (kibbles). Processing of the pulp includes grinding for animal feed production or roasting and milling for human food industry. The seeds have to be peeled which happens with acid or through roasting. Then the endosperm and the embryo are separated for the different uses.[1]
- ^ a b c d e f g h i j Cite error: The named reference
ipgriwas invoked but never defined (see the help page). - ^ a b Correia, P.J.; Gamaa, F.; Pestana, M.; Martins-Loução, M.A. (2010). "Tolerance of young (Ceratonia siliqua L.) carob rootstock to NaCl". Agricultural Water Management. 97: 910–916.
- ^ La Malfa, S.; Tribulato, E.; Gentile, A.; Gioacchini, P.; Ventura, M.; Tagliavini, M. (2010). "15N natural abundance technique does not reveal the presence of nitrogen from biological fixation in field grown carob (Ceratonia siliqua L.) trees". Acta Horticulturae. 868: 191–195.
- ^ a b c d e f g Droste, Rainer (1993). Möglichkeiten und Grenzen des Anbaus von Johannisbrot (Ceratonia siliqua L.) als Bestandteil eines traditionellen Anbausystems in Algarve, Portugal. (Göttinger Beiträge zur Land- und Forstwirtschaft in den Tropen und Subtropen ; Heft 87). Göttingen: Goltze.
- ^ http://www.sciencedirect.com/science/article/pii/S0308814605010824
- ^ Burg, Barbara. Good Treats For Dogs Cookbook for Dogs: 50 Home-Cooked Treats for Special Occasions. Quarry Books, 2007, p. 28
- ^ Heuzé, V.; Sauvant, D.; Tran, G.; Lebas, F.; Lessire, M. (October 3, 2013). "Carob (Ceratonia siliqua)". Feedipedia.org. A programme by INRA, CIRAD, AFZ and FAO. Retrieved October 3, 2013.