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Internal corrosion of tinplate container in canned mango (Mangifera indica) L. Nectar
Journal of The Science of Food and Agriculture
Abstract
Mango nectar prepared from Banganapalli variety caused less corrosion than nectar prepared from Badami or Raspuri variety. Degree of corrosion was inversely proportional to the viscosity of nectar. Among different fractions of mango pulp, only organic acid fractions were responsible for corrosion. β-carotene did not contribute to corrosion. Corrosion was more in pulp and nectar prepared from unpeeled mangoes. The peel contains gallic acid and ellagic acid of which the former acts as accelerator of corrosion. Rutin, catechin and pyracatechol acted as accelerators of corrosion but not quercetin. Leucopetunidin and leucopelargonidin have been tentatively identified in the mango peel and they did not affect the process of corrosion.
... The dissolution of iron and tin from tinplate cans filled with some foods are studied by many researchers, Madegowda et al. (2006) suggested that among different fractions of mango pulp, only organic acid fractions were responsible for corrosion. Corrosion was more in pulp and nectar prepared from unpeeled mangoes. ...
For a hundred years ago, man by test, experience and error screened steel for produce food containers, tin is a kind of steel use to make tinplate cans. However, tin have great problem, corrosion. Corrosion abounds in nature, it is a phenomenon appeared in tin cans, and that mean happened to large amounts of food cans. More attention will be give to corrosion happens in large quantities of canned foods packs under various headings. The tin-plate corrosion occur in two sides, either in the interior of cans containing food products; due to electro-chemical reaction; or exterior of cans; due to metal itself and environment conditions. In human health, internal reaction corrosion may be changing the organoleptic properties of food stuff and could be giving some toxicological problems. To protection of tinplates against corrosion there are many methods are frequently used in the food canning industry.
In the present investigation six amino acids have been used to investigate their inhibiting action on corrosion of tin plate in three fruit juices viz orange, mango and pine-apple by potentiodynamic method. All the amino acid used in present investigation showed > 94% IE. They showed either predominantly cathodic or mixed behaviour.
Tin has been mined and utilized from antiquity. The ancient metallurgists called it diabolus metallorum, the devil among metals, because its presence could make an alloy hard and brittle [1] and, to this day, we describe something to its detriment as being “tinny”. This so called “Cinderella” metal [2] finds application in plastics, alloys, solders, pharmaceuticals, etc (the world resources may last less than 50 years [3])but its most obvious role in modern society is in the production of tinplate for food preservation by canning. The initial discovery that decay of foodstuffs could be halted by heating them in sealed glass vessels was made in 1809 by Nicolas Appert, a Parisian confectioner and, the following year, an Englishman Peter Durand patented the idea of using “glass, pottery (or) tin” (tinplate) with Appert’s technique. The phenomenal success of this discovery is attested to by the fact that tin, a naturally non-ubiquitous element, is now present in small amounts in practically all animal life.
An investigation was carried out to study the corrosion behaviour of tin plate in citric acid in absence and presence of various concentrations of nitrate and sucrose and influence of glycine on tin corrosion in the presence of three fruit juices viz., orange, mango and pineapple by using Potentiodynamic polarization technique. The results of this investigation revealed that nitrate acted as weak inhibitor at 50 and 125 ppm concentrations and showed negligible inhibitory effect at 250 ppm of citric acid. Sucrose gave maximum inhibitory efficiency of 42% at 15% concentration. It was also found that glycine acted as an excellent corrosion inhibitor for tin plate, gave > 90% inhibitory efficiency in all the three juices studied and acted as cathodic inhibitor. This study indicated the possible use of glycine as corrosion inhibitor of tin containers in canning industries.
Fifteen amino acids, 5 organic acids, and 3 sugars were identified and measured quantitatively during and after the rest period of ‘Elberta’ peach and ‘Chinese’ apricot flower buds. Total amino acids increased just prior to the completion of rest in peach buds. Proline and alanine were the predominant amino acids in peach buds. Glutamic acid and proline were predominant during rest. Aspartic acid, serine, and phenylalanine increased considerably after rest was completed. Total organic acids increased slightly in peach buds after rest, while malic and citric acids showed considerable increases. In apricot buds, total organic acids increased 8-fold after the rest period was completed in mid-winter. Much of the increase which occurred, mainly in the last sampling before bloom, was attributed to fumaric, citric, pyruvic, succinic, and malic acids. After completion of rest, the sugars increased from 3- to 9-fold in peach and more than 2-fold in apricot buds.
Two levels of antioxidants, 0.02% and 0.002%, were added to a concentrated fish product. Two ways of incorporating antioxidants
into fish oil were studied. The oxidation rate of the samples was measured by using an oxygen analyzer and the thiobarbituric
acid test. The concentrated fish prepared from fresh mullet was stored for 0 hr, 48 hr, and 96 hr. The use of antioxidants
in a vegetable oil carrier did significantly slow the breakdown reaction of fish oil and lowered the oxidation rate of the
sample. When vegetable oil was used to serve as an antioxidant carrier, the high level of antioxidant (0.02%) stabilized the
fatty product more efficiently than the lower level (0.002%) did. At the level of 0.02% antioxidants, using soybean oil to
serve as antioxidant carrier, the fish product was quite stable during storage under the conditions of this study.
A procedure for the separation of 16 amino acids from a mixture, on a series of circular paper chromatograms by using different solvent mixtures is described. The solvent mixtures used are phenol-1-butanol-acetic acid saturated with water, benzyl alcohol-tert-amyl alcohol saturated with water, 1-butanol-acetic acid saturated with water, m-cresol saturated with pH 8.4 buffer, and phenol saturated with pH 12 buffer. The chromatograms of the unknown amino acid mixture and known mixture of standard amino acids are developed side by side on the same paper. For the quantitative determination of the amino acids the chromatograms are treated with ninhydrin and the colored bands due to each amino acid in the standard and unknown chromatograms are cut. The color is extracted with 5 ml. of 75% alcohol and estimated in a Klett-Summerson photoelectric colorimeter using 560 mμ. filter. The method yields highly reproducible results in the determination of the amino acid content of casein, in agreement with those reported by other workers.
Preliminary separation of the complex proanthocyanidins has been made possible by solvent fractionation using ethyl acetate and ethyl acetate containing ethyl alcohol. Subsequent paper chromatographic separation has yielded good results in the estimation of individual components. Besides leucocyanidin, leucopelargonidin and catechin have been detected in polymeric components.
Five selective spray reagents provide information regarding the A and B phenolic nuclei and the heterocyclic ring of flavonoid compounds. This information coupled with RF values in two solvent systems, enables the tentative identification of a wide variety of flavonoid substances. Lindstedt's bis-diazotised benzidine reagent gives colour reactions which are highly indicative of variations in the distribution of phenolic hydroxyl groups. The benzidine and ammoniacal silver nitrate reagents may be used with two-dimensional paper chromatography and a simple densitometer for estimating flavonoid compounds present in tannins and also the yield of phenols resulting from the degradation of flavonoid compounds and tannins. The benzidine reagent allows for the estimation of flavan-3-ols and flavan-3,4-diols of the phloroglucinol series in the presence of their counterparts of the resorcinol series.Additional factors in the correlation between structure and chromatographic behaviour of flavonoid compounds are described.
Thesis Central Food Technological Research Institute
- D Ph
- Mathew
‘The Mango-A hand book
- Daljit Singh
- Jermyn
- Carre