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Tomato seed cake, tomato seed meal, tomato seed presscake
Lycopersicon esculentum f. pyriforme (Dunal) C. H. Müll., Lycopersicon esculentum var. commune L. H. Bailey, Lycopersicon esculentum var. grandifolium L. H. Bailey, Lycopersicon esculentum var. pyriforme (Dunal) L. H. Bailey, Lycopersicon esculentum var. validum L. H. Bailey, Lycopersicon lycopersicum (L.) H. Karst., Lycopersicon lycopersicum var. cerasiforme auct., Lycopersicon lycopersicum var. pyriforme auct., Lycopersicon pyriforme Dunal, Solanum lycopersicum L.
Tomato seeds, a by-product of tomato processing (cannery, tomato paste, tomato juice, etc.), contain about 20-25% of an edible oil rich in linoleic acid (50-60%) and cholesterol (Lazos et al., 1998; Giannelos et al., 2005; Gunstone, 2006). The development of tomato processing in Italy and in the USA at the turn of the twentieth century led to an interest in tomato oil for soap-making and cooking, and in the use of tomato seed cake, the by-product of the oil extraction, in feeds and fertilizer (Rabak, 1917). Today, tomato seeds are usually mixed with the skins and pulp residue to make tomato pomace, and tomato seed oil has become a niche product, used notably in cosmetics. In recent years, there has been a renewed interest both in tomato seed oil for its nutraceutical properties and as a biofuel (Lazos et al., 1998; Giannelos et al., 2005), and in the protein of the seed cake, which is rich in lysine, and, when added to bread, improves loaf volume, texture and crumb quality, due to its anti-staling properties (Sogi et al., 2005).
Tomato seed cake has become a rare feed ingredient that should be available in regions where tomato seed oil is still produced. Production figures are lacking, but most of the recent research concerning tomato seed cake comes from Egypt (Anwar et al., 1978; El Moghazy et al., 1982; El-Din et al., 1997) and India (Rao et al., 1991; Sogi et al., 2005; Kaur et al., 2005).
Historically, the seeds were obtained after drying the pomace and separating the seeds from the skins and pulp using sieves and fans (Rabak, 1917). Newer processes may use a wet flotation and sedimentation system (Kaur et al., 2005). The dried seeds are then deoiled by mechanical extraction and, for a higher extraction rate, using a solvent. The resulting press cake is then ground (El Boushy et al., 2000).
Tomato seed cake is produced by different methods and its chemical composition is, therefore, variable. The deoiled oil cake was often mixed with the skins and other residues resulting in a product similar to the pomace but containing less oil, depending on the extraction rate (Rabak, 1917; El Boushy et al., 2000). True tomato seed cake has a high protein content (36-37%) as well as a high crude fiber content (22-28%). The residual oil content is in the 3-7% range and depends on the extraction process (Rabak, 1917; Anwar et al., 1978; Maymone et al., 1945; El-Din et al., 1997). The protein of the seed cake is rich in lysine (7% of the protein) but may be inadequate in methionine and cystine, especially for poultry (El Moghazy et al., 1982). Because of its high content of fibre, it is mostly used in ruminant feeding (Göhl, 1982).
Tomato seed cake, sometimes mixed with the pomace and molasses, was used to feed cattle in Italy in the first decades of the last century. Tomato seed cake was considered to be similar or superior to linseed cake for the feeding of dairy cows (Rabak, 1917). Like other tomato by-products, tomato seed cake has a somewhat bitter taste and should be used with more palatable feedstuffs. When first introduced, it should be sprinkled with salt and given in small proportions (Göhl, 1982). There have been no recent ruminant trials with tomato seed cake. Maymone et al., 1945 determined the OM digestibility to be rather low (55%), corresponding to a ME value of 9.2 MJ/kg DM.
Tomato seed cake contains large amounts of fibre, is deficient in methionine and should not be given to poultry at rates above 15%. Its ME value is quite low (6.49 MJ/kg DM). Feeding broiler chicks with a diet containing 34% defatted tomato seed cake depressed feed conversion and their performance (final body weight and average daily gain) was lower than those fed a diet containing cottonseed meal. The protein value of tomato seed cake-based diets benefited from the addition of DL-methionine (Anwar et al., 1978).
Avg: average or predicted value; SD: standard deviation; Min: minimum value; Max: maximum value; Nb: number of values (samples) used
| Main analysis | Unit | Avg | SD | Min | Max | Nb | |
| Crude protein | % DM | 37.0 | 1 | ||||
| Crude fibre | % DM | 28.3 | 1 | ||||
| Ether extract | % DM | 6.8 | 1 | ||||
| Ash | % DM | 7.4 | 1 | ||||
| Gross energy | MJ/kg DM | 20.8 | * | ||||
| Minerals | Unit | Avg | SD | Min | Max | Nb | |
| Calcium | g/kg DM | 1.6 | 1 | ||||
| Phosphorus | g/kg DM | 5.9 | 1 | ||||
| Amino acids | Unit | Avg | SD | Min | Max | Nb | |
| Arginine | % protein | 5.3 | 1 | ||||
| Histidine | % protein | 1.9 | 1 | ||||
| Isoleucine | % protein | 3.3 | 1 | ||||
| Leucine | % protein | 7.6 | 1 | ||||
| Lysine | % protein | 7.2 | 1 | ||||
| Methionine | % protein | 0.2 | 1 | ||||
| Phenylalanine | % protein | 3.8 | 1 | ||||
| Threonine | % protein | 3.4 | 1 | ||||
| Tryptophan | % protein | 0.9 | 1 | ||||
| Tyrosine | % protein | 4.1 | 1 | ||||
| Valine | % protein | 4.4 | 1 | ||||
| Ruminant nutritive values | Unit | Avg | SD | Min | Max | Nb | |
| OM digestibility, Ruminant | % | 55.2 | 1 | ||||
| ME ruminants (FAO, 1982) | MJ/kg DM | 9.2 | 1 | ||||
| Nitrogen digestibility, ruminants | % | 72.0 | 1 | ||||
| Pig nutritive values | Unit | Avg | SD | Min | Max | Nb | |
| Energy digestibility, growing pig | % | 45.7 | * | ||||
| DE growing pig | MJ/kg DM | 9.5 | * |
The asterisk * indicates that the average value was obtained by an equation.
References
Maymone et al., 1945; Williams, 1955
Last updated on 24/10/2012 00:45:15
Tran G., 2015. Tomato seed cake. Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://www.feedipedia.org/node/690 Last updated on October 13, 2015, 10:05