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Samples of loomstate cotton fabric were first treated with aqueous potassium permanganate solution at different concentrations in the presence of a non‐ionic wetting agent. The samples were then washed and treated using solutions containing methacrylic acid, wetting agent and acid or basic dye along with citric acid of different concentrations at different temperatures for different times. The critical properties of the fabric such as graft yield (expressed as carboxyl content m.eq/100g cellulose), colour strength before and after soaping and percentage loss in colour strength due to soaping were found to depend on the concentrations of KMnO₄, citric acid and methacrylic acid as well as duration of the treatment. Based on the results obtained, treating formulations consisting of KMnO₄ (0.1g/l), citric acid (0.1g/l), methacrylic acid (50 per cent), dye (1 per cent) and wetting agent (2g/l) was considered appropriate for concurrent grafting and dyeing of the said fabrics provided that the treatment was carried out at 90°C for 60 minutes.

We publish below a Circular which has been issued by the Ministry of Health (Circular No. 325), addressed to the Town Clerks of the various Councils, urging the Councils not to take actions against vendors of adulterated milk except in cases where it has been proved by repeated sampling that the milk from such vendors is consistently below the legal standard. A more stupid and damaging circular it is not possible to conceive, and the matter is one which calls for very strong representations being made by the Councils throughout the country. The effect of adopting the recommendations of the circular in question would be to practically stultify the Food and Drugs Acts in so far as the sale of adulterated milk is concerned, and it would further encourage the dairy farmer to keep certain breeds of cows which are well known for the very large quantity of milk which they produce of poor quality. The mixed milk from a properly selected herd of cows which are properly fed will never fall below the extremely lenient standard fixed by the Board of Agriculture. Whether the production of inferior or adulterated milk is due to the extraction of cream, the addition of water, improper feeding or improper selection of the cows, is of no moment to the consumer, the motive for the adoption of any of these methods is pecuniary benefit. If the desire of the Ministry of Health is to encourage adulteration and sophistication of food and to bring to nought what little protection is afforded to the consumer by the administration of the Sale of Food and Drugs Acts, a more effective Circular could hardly have been issued.

The purpose of this paper is to supplement the scant previous investigations on the corrosion behaviour of 2205 and 2507 duplex stainless steels in selected organic acids containing chloride additions.

Microstructural examination of the alloys was first carried out, after which the corrosion behaviour of the alloys in citric, oxalic, formic and acetic acids containing chloride additions at varying temperatures was studied using electrochemical techniques.

The alloy 2507 material had a larger grain size than did the alloy 2205 sample. The corrosion resistances of the alloys generally are highest in acetic acids and lowest in citric acid. The addition of chloride had a pronounced effect on their corrosion resistance. Alloy 2507 generally exhibited higher corrosion resistance in all of the acids than alloy 2205, with the exception of acetic acid at room temperature. The 50:50 ratio of ferrite to austenite composition, as revealed by phase compositional analysis, indicated no significant possibility for galvanic corrosion between the phases. This suggests that the corrosion behaviour of the alloys is controlled by their grain sizes and chemical compositions.

Although the corrosion behaviour of duplex stainless steels in some organic acid media has been reported, this investigation covers the major organic acids not previously reported. Since in real industrial systems a mixture of both organic and minerals acids/salts may typically exist, investigations of the combined effect of chloride ions with the organic acids reported in this paper typify real industrial operations. The paper thus provides a basis for material selection for the application of 2205 and 2507 in industrial systems where organic acids are mostly used.

A good solder flux must simultaneously perform a number of important functions. It must promote thermal transfer to the area of the solder joint, enhance wetting of the solder on the base metal, and prevent oxidation of the metal surfaces at soldering temperatures. However, its primary task is to remove the tarnish layer from the metal joint that is about to be soldered. Despite the fact that the process of soldering electronic devices is a part of a multi‐billion dollar industry, the actual chemical reactions that occur during this cleaning process are not well documented. In the case of organic acid or water‐soluble fluxes, the flux reactions can be modelled by considering the interactions at the metal/metal oxide/electrolyte solution interface. Although such modelling systems have not frequently been applied to the behaviour of solder and fluxes, they are common for a number of other closely related chemical systems which are of practical interest, e.g., passivation layers on metals, electrochemical cells and metal oxide semiconductors. There are two types of reactions that can occur at the oxide/solution interface: acid‐base reactions and oxidation‐reduction reactions. The factors which affect the reaction rates and mechanisms are such variables as the structure of the metal oxide, temperature, pH, concentration of the electrolyte, and the chemical nature of the solute and solvent. By combining information about flux behaviour with available models of surface reactions, it should be possible to develop the theory of the flux reactions and to gain a better understanding of the factors which control the process.

The purpose of this paper is to determine the level of food additives, caffeine and total sugars in locally manufactured beverages in Mauritius and ascertain their compliance with national and international norms.

In total, 48 beverages: 21 soft drinks, 14 ice teas, 5 fruit drinks, 5 nonalcoholic sparkling drinks and 3 tonic waters were analysed for the level of sweeteners (aspartame, acesulfame K and saccharin), preservatives (benzoic and sorbic acid), colours (tartrazine, sunset yellow, quinoline yellow, allura red, amaranth, ponceau 4R, carmoisine, erythrosine, brilliant blue, green S and patent blue), citric acid, caffeine and total sugars. High-performance liquid chromatography methods used to quantify the levels of total sugars, caffeine and additives were validated against parameters such as linearity, recovery, accuracy, precision and limit of quantification.

Out of 48 beverages, 13 contained at least one sweetener. The most frequently used sweeteners were acesulfame K and aspartame. Benzoic acid was present in 27 samples (42.32–168.03 mg/L). Sorbic acid was present in 14 beverages (13.01–180.38 mg/L). Citric acid (0.7–4 g/L) was present in all the 48 beverages, while caffeine was present in 20 samples in the range of 14.01–129.42 mg/L. Nine samples contained at least one artificial colour and the most frequently used colours were tartrazine, sunset yellow, brilliant blue and carmoisine. The average level of total sugars present in the beverages was 10 g/100 ml. The validation parameters obtained showed evidence for method suitability.

Beverages sold by individuals on the street, small restaurants and markets were not analysed.

This study provides an overview of the chemical composition of soft drinks and their compliance with Food Regulations. It also paves the way to investigate weaknesses, knowledge, attitudes and practices of local manufacturers, which leads to non-adherence to Regulations regarding food additives.

The purpose of this paper is to observe the colour and thermal stability of natural red dye consisting of anthocyanin with addition of different aqueous acids and applied as coating films.

The natural red dye was extracted from Hibiscus sabdariffa L. (roselle) flowers and mixed with 1 per cent hydrochloric acid, 5 per cent acetic acid, 5 per cent citric acid and 5 per cent oxalic acid. All the dye samples were exposed to heat and UV-B to observe the colour stability by calculating the half-life and rate of reaction. In coating film application, each of the dye samples was mixed with 25 wt% of poly(vinyl alcohol) (PVA) and applied on to a glass substrate. The coating samples’ colour stability was observed by using CIE L*a*b* colour space coordinates. The coating films’ weight loss stability against temperature was observed by using thermogravimetric analysis.

Addition of hydrochloric acid enhances the thermal and UV stability of the anthocyanin natural dye. This can be observed from the calculation of the half-life of the dye. The half-life values for the thermal and UV stability studies were 1,155 hours and 210 hours, respectively. In coating films, the sample with addition of acetic acid showed the highest colour stability with colour difference (ΔE*) value 8.95.

The coating films developed in this work are not suitable to be applied on metal substrates due to the presence of water, which can contribute to the corrosion formation.

The coating films developed in this work are suitable for washable coating application. In other words, they are non-permanent coatings applied on a glass substrate.

Development of water-based coatings from PVA binder with anthocyanin colourant is introduced in this study.

The purpose of this paper was to determine and compare nutritional composition of different parts of citrus fruits, namely, Citrus aurantium (peel: albedo, flavedo and pulp: juice, pomace) . This study was conducted through three stages of fruit maturity (green, yellow and orange). Total polyphenols, flavonoids, β-carotene, total chlorophyll, ascorbic acid, acidity, total soluble solid and the minerals (Ca, Mg, Zn, Na, K, Fe, Mn Cu) were evaluated. Moreover, the relationship between the total polyphenol, flavonoids and the antioxidant activity was determined.

Total polyphenols were determined by the Folin-Ciocalteu method. Flavonoids were assessed by the aluminum chloride colorimetric method. Ca, Mg, Zn, Fe, Mn and Cu were measured using an atomic absorption spectrophotometer. K and Na contents were determined by using a flame photometer. Other nutritional composition was determined by volumetric method.

The result showed that the concentrations of antioxidants, total polyphenols, flavonoids, vitamin C, total chlorophyll, total acidity and antioxidant activity (DPPH%) decreased during the maturity of fruit while the value of pH and β-carotene increases. In addition, the concentrations of the most minerals decreased through the maturation of fruit except Na. Anova statistical analysis of all the studied chemical variables was shown significant differences between all the samples. The pH, total soluble solids, β-caroteniod: orange juice had the highest average while green juice had the lowest. Ascorbic acid, total acidity, total chlorophyll: green juice had the highest average while orange juice has the lowest. Total phenol, K, Mg, Fe, Cu, Mn: green flavedo had the highest average while orange juice had the lowest. Flavonoid, antioxidant activity (DPPH%), Ca, Zn: green albedo had the highest average while orange juice had the lowest. Na: orange flavedo had the highest average while green juice had the lowest. The correlations between total polyphenol, flavonoid and antioxidant capacity were significantly higher (R = 0.935 and 0.960, respectively).

The stage of maturity affects nutritional composition in Citrus aurantium fruits (C. aurantium) peel and pulp, where some minerals of composition increased and others decreased, according to the results. This is the first study on comparing the nutritional composition of pulp: juice, pomace and peel: albedo, flavedo of Citrus aurantium L. during maturity in Syria, and it was also not found in previous works.

Sargassum fusiforme is a popular edible seaweed in coastal cities of China that contains diverse nutrients including iodine. Cooking is an effective way to improve food safety, but it can alter both the contents of elements along with speciation and bioavailability. Three common cooking methods, the soaking, steaming and boiling, were evaluated for their effects on the protein structures, protein digestibility, iodine content and iodine bioavailability of S. fusiforme.

Fourier transform infrared spectroscopy was used to study the structural changes of protein, and an in vitro digestion/Caco-2 cell culture system was used to evaluate the digestibility of protein, bioaccessibility and bioavailability of iodine.

Boiling and steaming altered the protein secondary structure demonstrated by increased a-helix and random coil and decreased β-sheet, which improved the in vitro protein digestibility. Iodine content was reduced by cooking, with the highest loss observed after boiling, followed by soaking and steaming, while it was found that both bioaccessibility and cellular uptake of iodine were significantly elevated by boiling and steaming using an in vitro digestion/Caco-2 cell culture system. The presence of ascorbic acid, citric acid or tyrosine was beneficial for the iodine absorption, while oxalic acid and phytic acid hindered the iodine bioavailability.

The present finding suggested that cooking was conducive to the digestion and absorption of iodine in S. fusiforme. In addition, different dietary factors could have a certain impact on the absorption of iodine. Results of the study are essential for improving the application value of S. fusiforme to ensure reasonable consumption of seaweeds.

An upsurge in health and environmental concerns over the use of synthetic color has made the development of color from cheap and easily available natural sources, namely, plants, animals, micro-organisms and algae as indispensable. This study aims to extract anthocyanins, an important natural plant pigments, from Sohiong (Prunus nepalensis). This study demonstrated that Sohiong have high anthocyanins content and antioxidant property, indicating an immense potential for the fruit producers and food processors.

Response surface methodology was used to optimize the conditions for extraction of anthocyanins from Sohiong using conventional solvent extraction.

The optimum conditions for extraction were found to be 36.75°C temperature, 60.32 per cent ethanol concentration and 2.39 per cent citric acid concentration with recovery of 45 per cent total extract yield, 858.84 mg C3G/100g DM anthocyanin content and 824.91 mg GAE/100g DM phenolic content with in-vitro antioxidant activity of 31.40 mmol AEAC/100g DM for FRAP and 84.66 per cent DPPH scavenging capacity (20mg/ml). The F-values and high values of adjusted determination coefficient for each response imply high level of significance of the fitted models.

Extracted color can be used in food and pharmaceutical industries.

Pigment extracted is from a natural source and possesses high antioxidative activity and potential health benefits. With increasing demand for natural colors and other additives, there is a wide range of applications of the pigment as natural colorant in the food and pharmaceutical sector.

Selected plant source, i.e. Sohiong, was not used earlier by any researcher to extract anthocyanins for potential applications as food colorant.

The question whether grape juice may or may not be preserved with sulphur dioxide is one which arises occasionally as a result of a certain ambiguity in the wording of the First Schedule of the Regulations. It is not a matter of opinion, as some would hold, but a matter of law, and, as such, should be fully appreciated by the legal advisers of local authorities, if not by Public Analysts. Item 4 of the First Schedule of the Regulations states that “Unfermented grape juice and non‐alcoholic wine made from such grape juice if labelled in accordance with the rule contained in the Second Schedule to these Regulations” may contain 2,000 parts of benzoic acid per million of grape juice and does not admit of the presence of the addition of any sulphur dioxide. The Second Schedule prescribes that, if the proportion of benzoic acid present in grape juice exceeds 600 parts per million, it shall be labelled with a declaration to that effect and also with the words “and is not intended for use as a beverage.” Item 5 of the First Schedule of the Regulations states that “Other non‐alcoholic wines, cordials and fruit juices, sweetened or unsweetened” may contain either 350 parts of sulphur dioxide per million parts of preparation or 600 parts per million of benzoic acid. Normally one would infer from this that grape juice to be used as a beverage falls under Item 5 of the Regulations, but that, if for some special reason it is not to be so used, it is permitted to contain up to 2,000 parts per million of benzoic acid provided that it is labelled to the effect that it is not to be used as a beverage. It should be noted that Item 4 does not read that grape juice and non‐alcoholic wine made from it may contain 600 parts per million of benzoic acid, but that, if labelled in accordance with the rules contained in the Second Schedule, it may contain 2,000 parts of this preservative. If grape juice were only allowed to contain benzoic acid as a preservative and if sulphur dioxide were prohibited under all circumstances one would have thought that Item 4 of the First Schedule would have been drawn up to indicate this, but no such indication is given at all. At the time that the Preservatives Regulations were issued it was fully recognised that sulphur dioxide was employed as a preservative in grape must. Whilst the Departmental Committee was considering the matter of preservatives and colouring matters the Ministry of Health issued a Report on Public Health Subjects, No. 24, entitled “Report on the Composition of Commoner British Wines and Cordials (Alcoholic and Non‐alcoholic),” by Dr. G. C. Hancock, C.B.E., one of the Medical Officers of the Ministry, together with a Report by the Government Chemist on the Examination of Samples. In the introduction Dr. G. Newman, the Chief Medical Officer to the Minister of Health, writes : “The most important of these materials are preservatives, and Dr. Hancock mentions the considerations which underlie the use of these substances in the manufacture of British wines and cordials. As, however, the question of preservatives and colouring matters in foods is being considered by a Departmental Committee of the Ministry he has made no specific recommendations relating to the use of these substances.” On page 4 at the end of the sixth paragraph Dr. Hancock refers to grape juice or must and says : “It is sent here in a highly concentrated form and is usually ‘sulphured,’ i.e., treated with sulphur dioxide in order to inhibit fermentation during transit.” Among other information placed at the disposal of the Departmental Committee was Dr. Hancock's report and in the Final Report of the Committee, also issued in 1924, paragraph 57 states: “Sulphurous acid and sulphites are extensively used in beer and alcoholic wines, to some smaller extent in non‐alcoholic beverages, and in preserving fruits and fruit juices, dried fruits, gelatine and sausages. … In the case of beer, wines, fruit and fruit juices the introduction comes partly from the treatment of the vessels of preparation and storage, partly from the materials used and partly from the actual addition of preservative in the course of manufacture or treatment for storage.” When considering the question of alcoholic wines, Foreign and British in detail, the Committee stated their opinion in the following words (para. 144): “Foreign and British wines are by no means closely related products. The former are the naturally fermented produce of the grape, while the latter are rarely derived from fresh fruit and are far more commonly prepared from a basis of dried fruits, rhubarb or imported grape must, fermented after the addition of sugar and flavouring materials, such as dried ginger‐root, orange peel, alcoholic essences or foreign wines. Considered from the point of view of preservatives, however, they have two features in common, (a) that the alcoholic content is very similar in each, (b) that sulphur dioxide is the preservative which is usually favoured (in addition to the alcohol present) to prevent secondary and other undesirable fermentations and sourness.” Instead of making any suggestion that the use of sulphur dioxide should be prohibited in grape must, the Committee draw their conclusion in paragraph 147 in the following words : “Our conclusion is that while in general preservatives should be unnecessary in alcoholic wines of ordinary strength, there may be circumstances which render the entire elimination of preservatives impracticable for the present. We think, however, that no other preservatives than sulphur dioxide should be permitted, and that this substance should not be present in amounts exceeding 3 grains of sulphur dioxide free and combined per pint (343 milligrams per litre).” This recommendation was adopted in the Draft Statutory Order issued in February, 1925, but, when the final Order was published, the quantity of sulphur dioxide permitted had been increased to 450 parts per million, making the law in this country agree with that already adopted in France. The recommendation made by the Departmental Committee was put forward after the Committee had commented on the fact that British wines are largely prepared from “imported grape must.” It seems remarkable that the Committee should have expressed the opinion that sulphur dioxide is used for sulphuring the casks, that sulphur dioxide is permitted in the completed wine, if it is not allowed to be present at intermediate stages, and that a Regulation was made by which benzoic acid only could be present in the unfermented grape juice, if this is not permitted to be present in the fermented alcoholic wine. When benzoic acid has once been added it cannot be eliminated and, as recognised by the Departmental Committee, benzoic acid is undesirable from the fermentation aspect. Had there been any intention to prohibit the presence of sulphur dioxide in unfermented grape juice, the Regulations would have rung the death‐knell to the manufacture of British wines, which have been produced in increasing volume during the last twenty years. Further, if there had been any intention to prohibit the addition of sulphur dioxide to grape juice, one cannot but express surprise that the importation of such juice has not been suppressed long ago by the Customs Authorities, since Section 8 (1) of the Regulations lays the responsibility for the control of Imported Articles of Food on the Officers of Customs and Excise and, through them, on the Government Chemist. The failure of the Government Chemist to condemn grape must containing sulphur dioxide cannot be due to his ignorance of its presence because the chemical analyses for Dr. Hancock's Report were carried out by the Government Chemist, and on page 58 of the Report No. 24, to which reference has already been made, analyses are given of two French musts containing 360 and 302 parts of sulphur dioxide per million respectively and of an American concentrated must containing 63 parts of sulphur dioxide per million. If we now look at paragraph 153 of the Final Report of the Departmental Committee we find that the matter of preservatives in certain non‐alcoholic beverages is dealt with in the following words: “We consider that sweetened and unsweetened fruit juices, syrups, cordials, non‐alcoholic wines and articles of similar composition such as certain well‐known proprietary cordials, are peculiarly liable to develop moulds and to ferment, owing to liability to exposure on the consumer's premises between the first opening and final consumption, and we think that on this account they may under present trade conditions need the addition of a small proportion of preservative. We therefore suggest that the presence either of benzoic acid up to 5 grains or of sulphur dioxide up to 3 grains per pint might be considered.” These recommendations were adopted in the Draft Rule and Order, issued in February, 1925, and there was no reference in this Draft indicating that grape juice was to be treated in any manner distinct from other fruit juices. The introduction of Item 4 in S.R. & O. 1925, 775, came as a complete surprise to everyone and the general surprise felt was mentioned by Mr. C. A. Mitchell (now Dr. Mitchell) in a paper read before the Medico‐Legal Society on Tuesday, April 20th, 1926, with the Rt. Hon. Lord Justice Aitken in the chair. Mr. Mitchell made the following statement: “The fourth item in the Schedule is one at which one can only stare and wonder how it ever came there. According to this regulation unfermented grape juice and non‐alcoholic wine made from it, may contain the enormous quantity of 17 grains of benzoic acid per pint, provided that it is labelled in accordance with Schedule II. I am fairly familiar with the cases which have been brought into Court during the last 20 years, but I cannot recall an instance of a non‐alcoholic wine (labelled or unlabelled) containing an amount of preservative equivalent to this quantity of benzoic acid.” Mr. Mitchell then proceeds to explain that the most probable reason for the introduction of this item into the rule is that it is intended to apply to non‐alcoholic sacramental wine, which is not to be used as a beverage, but which is taken a little at a time and is expected to keep for long periods, when the bottle has once been opened. This is, in fact, the position so far as I am aware and there was never any intention of any restriction on the use of sulphur dioxide in the ordinary way as a preservative in unfermented grape juice so long as the amount present did not exceed 350 parts per million.