Tin-free Steel Cans Research Articles

Effect of thermal processing on quality of tender jackfruit in tin-free-steel cans.

Thermal processing is the most efficient and economical technique for the long-term preservation of tender jackfruit in ready-to-cook form on a commercial-scale. Although, thermal processing primarily focus on microbiological safety of the product, the associated quality changes need to be examined as it is decisive of consumer acceptance. The present study investigated the effect of two pasteurization (90 and 100°C) and sterilization temperatures (110 and 121°C) at different lethality on microbiological, colour, texture, ascorbic acid (AA), total flavonoid (TFC) and phenol (TPC) contents of tender jackfruit processed in tin-free-steel (TFS) cans. Time required for thermal processing was computed from respective heat penetration curve. Thermal processing improved both the TFC and TPC of tender jackfruit, while colour, texture and AA had degraded. Based on microbiological and physicochemical quality analyses, the study adjudged pasteurization at 90°C for 19min and sterilization at 121°C for 8min as the best temperature-time combination for thermal processing of tender jackfruit in TFS cans.

Modeling corrosion trends in tin‐free steel and tinplate cans containing tomato paste via adaptive‐network‐based fuzzy inference system

AbstractCorrosion process in metallic cans is one of the most significant issues, which is of utmost importance in food packaging; meanwhile, it can be studied through both economical and hygienic aspects. Designing a method to determine this process in an acidic food like tomato paste might be a good standard to monitor this phenomenon in food products. Accordingly, in this article, tin‐free steel (TFS) and tinplate (TIN) cans containing tomato paste were incubated at three different temperatures (25, 35, and 45 °C) and three filling percentages (85, 90, and 95%). Corrosion rate was then studied via image processing method within six months, thereupon corrosion modeling was carried out using adaptive‐network‐based fuzzy inference system (ANFIS). Time, temperature and filling percentage were considered as the input parameters, on the other hand the corrosion rate was assumed as the output. Multiple training cycles and various membership functions were used in the form of trial and error to have the models optimized. Having the models been examined, trapezoidal membership functions with 3–3–3 functions for TFS cans and 2–2–2 functions in Tin cans were determined as the best models. High coefficients of determination (R2 = 0.97) between experimental and predicted values by optimum models presented a robust method for monitoring corrosion in metallic cans.Practical applicationsFood products might be preserved in metallic cans for more than 2 years without any significant changes in organoleptic properties. One disadvantage is that cans are more susceptible to corrosion compared with other packaging materials. The absence of appropriate methods and the high costs of analytical instruments are major problems encountered in evaluating the corrosion process. On the other hand, developing straightforward and modern techniques may be an efficient solution in this area. This study was devoted to the prediction of the corrosion process using two prevalent can plates employed in the food industry. ANFIS modeling was implemented in tomato paste, which exhibits acidic and corrosive behavior. ANFIS modeling may be an onset for further research in this area to engineer and manufacture intelligent sensors by which on‐line monitoring in complex and nonlinear interactions is undertaken.

Effect of thermal processing on the biochemical constituents of green mussel (Perna viridis) in Tin-free-steel cans.

The effect of thermal processing on the biochemical constituents of green mussel (Pernaviridis) in brine was investigated. Depurated mussel samples were thermal processed in tin-free steel cans (TFS) at F0 8.43. The time temperature data was collected during heat processing using EVAL data recorder and heat penetration characteristics were determined using formula method. The total process time was 27.48min and the processed cans were found to be commercially sterile. The mineral composition of processed mussel was significantly higher than raw samples. The instrumental texture analysis indicated that product become soft after thermal processing.The thermal process led to a significant decrease in total amino acid and fatty acid content of the samples. Even though the samples showed a decrease in amino acid and fatty acid composition after thermal processing, the mussel meat was nutritionally well balanced with respect to essential anino acids and fatty acids.Hence the product can be considered as a food source with high quality protein and fat to fulfil consumer's requirements.Based on sensory analysis, the processed products were found acceptable during the study period.

Microbial Studies of Prepared Curries Stored in Tin Free Steel Cans

Apart from the nutrient analysis microbial study is very much essential to know the microbial contamination after storage. So in the present study it is aimed to investigate the microbial contamination in the prepared fish and shellfish curries stored in tin free steel cans. The prepared curries of fish, shrimp, crab and mussel were stored in TFS cans at room temperature (30 ± 2°C) for a period of 18 months. During storage the cans were periodically checked in the intervals of 3rd, 6th and12th months especially the visual signs of internal and external rusting like appearance of can walls, adhesion of product to the can walls and internal rusting. About eight cans were selected at random from each batch processed to different Fo values. Four cans from each batch were incubated at 55°C for 4 days and another four were incubated at 37°C for 14 days. The incubated cans were opened under aseptic conditions and the samples were transferred to sterile thioglycollate broth tubes. Then a layer of sterile liquid paraffin was applied in each tube so as to create anaerobic condition. The tubes were then incubated at 37°C for 48 hrs and observed for any development of turbidity, which indicates survival of microorganisms. Tubes not showing any turbidity were incubated for further 48 hrs at 37°C to ascertain the sterility. Besides the above microbiological quality was assessed from the fish, shrimp, crab and mussel curries by standard plate count, t otal coliform count and totalfungal count, according to APHA. The microorganisms are totally absent in the present study for short and longer time storage (3 to 18 months) of fish and shellfish curries stored in TFS cans. Apart from that there is no internal and external rusting, texture during the storage period. So it is conform that TFS cans are suitable to store the fish and shellfish products as evidence by no microbial growth and also not affecting the nutritional quality of the stored food.

Feasibility of Fish and Shellfish Curries Stored in Indigenous Polymer Coated Tin Free Steel Cans

The study indicated that the suitability of indigenous polymer coated TFS cans for processing at high temperature and pressure. The cook value was found to exhibit an inverse relationship with processing temperature (p<0.05) and was maximum at 115°C and minimum at 130°C. The fish products were acceptable even after 24 months of storage at ambient temperature. The initial overall acceptability score of about 8.75 and it was gradually reduced to around 6.78. It can be seen that the initial pH of fish, shrimp, crab and mussel curries are 5.9, 5.7, 5.6 and 6.0 respectively indicating that it is towards the acidic side. The acidic nature of the product can be attributed to the acidity contributed by the curry ingredients like tomato. During storage, the pH of the products was found to exhibit a decreasing trend. On the 6th, month of storage, the pH of fish, shrimp, crab and mussel curries are 5.7,5.6, 5.6 and 5.8 respectively which are significantly lower as compared to initial values. On the 12th month of storage, the pH of fish, shrimp, crab and mussel curries are 5.6, 5.6, 5.5 and 5.7 respectively. The results of the present experiments showed that the polymer coated TFS cans are suitable for processing fish products. Polymer coated TFS cans was found to withstand all the conditions of thermal processing. The TFS cans which are now available in India can be used for thermal processing of various fish products as a substitute to other packs.

Influence of Heat Penetration on the Quality of Canned Ribbon Fish (Trichiurus lepturus )

Influence of heat penetration on the quality changes of ribbon fish canned in different media, oil and curry using tin-free steel cans, was assessed. The total process time for ribbon fish in oil pack was 47 min, and curry pack was 68 min, with a lethality value of 12.84 and 10.8 min for oil and curry pack, respectively. The biochemical and sensory analysis of the products was done during a storage period of 5 months. Total volatile base nitrogen and tri-methylamine nitrogen contents were found to be slightly higher but within the acceptable limit at the end of 5-month storage, while thiobarbituric acid and free fatty acid content increased slightly in curry and oil pack at the end of the storage period. The sensory quality of the processed products was rated as good by the taste panel, and the products were in acceptable condition even after storage of 5 months at room temperature (28 ± 2C). Practical Applications The present work on the development of ready-to-serve ribbon fish canned products will help in meeting the present demand in the market; if commercialized, it may be a better method of utilization of this presently underutilized fish to fetch higher value to both fishermen and processor besides providing a new and low cost raw material base to canning industry as well as it forms a means of diversification. It was found that tin-free steel cans are suitable for processing fish products, so they can be used as an alternative to tin and aluminum cans because of their capacity to withstand all the conditions of thermal processing.

Development of a process for shelf stable dairy dessert dalia and its physico-chemical properties

Dalia, is a traditional dairy food of Indian sub-continent. It is consumed as dessert by cooking cracked wheat (dalia grains) in milk along with addition of sugar. It is used as a breakfast food especially for growing children and also for old age people. It has a poor shelf life of 1–2 days. In order to enhance its shelf life, dalia was processed in tin-free steel cans at 121.1 °C in a rotary over pressure retort. Process lethality (Fo) was found to vary from 3.90 to 8.22 min for different formulations. The average composition of retort sterilized dalia dessert comprised of 29.60 g/100 g total solids (TS), 3.56 g/100 g protein, 0.84 g/100 g ash and 21.54 g/100 g total carbohydrates including 2.88 g/100 g amylose. The product had a short lag period for the heating curve, jh (0.40–0.85), small heating rate index, fh (3.2–5.5 min) and a short lag factor for the cooling curve, jc (0.91–1.10) implying essentially convective heating regime. The process time (B) was 10.20–15.78 min for Fo value of 3.90–8.22 min, whereas the cook value (Cg) was 28.95–54.03 min. Fo value of 4.15 min and nisin 376 IU/g yielded a product that was both safe and wholesome for 72 days at 37 °C.

Proximate Composition of Fresh and Prepared Meats Stored in Tin Free Steel Cans

It is advisable to estimate the nutrient quality after storage, to know the influence of stored food on cans or containers. So it is planned to study the proximate composition of fresh and prepared meats of fish and shellfish stored in tin steel free cans. Protein (fresh meat 36.66% and cooked meat 32.6%), carbohydrate (fresh meat 1.17% and cooked meat 0.65%) and moisture (fresh meat 70.41% and cooked 42.41%) were maximum in fresh meat. However, lipid (fresh meat 2.95% and cooked 5.75%) and ash (fresh meat 4.41% and cooked meat 11.11%) showed maximum concentration in cooked meat of fish. Protein (fresh meat 36.14% and cooked meat 32.9%), carbohydrate (fresh meat 2.11% and cooked meat 0.86) and moisture (fresh meat 75.18% and cooked meat 69.18%) were maximum in fresh meat. However, lipid (fresh 1.40% and cooked meat 2.92%) and ash (fresh meat 3.8% and cooked meat 4.5%) showed maximum concentration in cooked meat of shrimp. Protein (fresh meat35.85% and cooked meat 20.25%), carbohydrate (fresh meat 2.58% and cooked meat 0.87%), lipid (fresh meat 2.44% and cooked meat 1.14%) and moisture (fresh meat 78.26% and cooked meat 64.51%) were maximum in fresh meat. However, ash (fresh meat 7.62% and cooked meat 11.20%) was maximum in cooked meat of crab. Protein (fresh meat 56.11% and cooked meat 40.20%), carbohydrate (fresh meat 8.5% and cooked meat 3.11%), and moisture (fresh meat 80.11% and cooked meat 49.11%) were maximum in fresh meat. However lipid (fresh 12.67% and cooked meat 38.33%) and ash (fresh meat 2.62% and cooked meat 4.10%) showed maximum concentration in cooked meat of mussel.

Studies on thermal processing of tuna - A comparative study in tin and tin-free steel cans

Tin -free steel can is an ideal alternative to open top sanitary t in cans (OTS) for thermal processing of little tuna ( Ethynnus affinis ) in curry used as filling media. Effect of heat penetration on physical, biochemical and sensory characteristics of canned tuna product were studied. The chemical analysis of raw tuna fish showed a protein content of 24.20 % and a lipid content of 1.37%. Comparatively, tuna used in the present study is more suitable for canning due to the presence of more protein and less fat in its flesh. Precooking is an important step in general canning process as it serves to reduce moisture content along with inhibiting enzymatic reaction, decreasing microbial load and cleansing the meat. The protein content of precooked tuna was 2.92% more than raw tuna due to relative concentration of moisture content decreases due to precooking. The percentage of yield of light meat and dark meat was 36.58% and 10.18% from whole cooked tuna and the same for dark and white meat was 28.40%. Tuna in curry packed in two metal container s subjected to thermal processing at 115 0 C for 70 minutes . The F 0 (slowest heating point) values for canned tuna in curry packed in TFS and Tin cans obtained were 10.13 and 10.23 minutes and cook values were 145.5 minutes &amp; 153.6 minutes respectively . During the storage period, the total volatile base nitrogen, trimethyleamine nitrogen, free fatty acid values were found to increase, while thiobarbituric acid value decreased and pH was slightly acidic . There was no significant difference (p&lt;0.05) in appearance, colour, odour, taste, flavour, texture, overall quality of the raw tuna and final products. However, both canned products were acceptable even after storage of 5 months at ambient temperature and also , the product remained commercially sterile. It was concluded that according to quality of the product and heat penetration studies, tin - free steel container can be used as alternative to the open top sanitary tin cans for canning tuna meat.

STANDARDIZATION OF PROCESS PARAMETERS FOR READY-TO-EAT SHRIMP CURRY IN TIN-FREE STEEL CANS

Polymer-coated tin-free steel cans were evaluated for their suitability for canning and storage of ready-to-eat fish products. The cans were found to withstand the thermal processing conditions and suitable for food contact application. The overlap was 63%, which was well above the prescribed limit of 45%. Blanched shrimps were used for preparing three different styles of shrimp curry from which one was selected based on sensory evaluation. Shrimp curry prepared according to the standard recipe was processed to three different F0values of 6, 7 and 8 at 121C in polymer-coated tin-free steel cans. The thermal history during heating and cooling was collected using a data recorder. Raw, blanched and processed shrimp was subjected to analysis of color, texture and shear force by using instrumental methods. Analysis of the Commission Internationale d' Eclirage L*, a*and b*color values showed that the duration of exposure to heat treatment influenced the color parameters: the lightness (L*) and yellowness (b*) decreased, and the redness (a*) increased with increase in heating time. Upon blanching, the instrumental texture and shear values increased and then reduced on thermal processing with the increase in the duration of exposure. Shrimp curry processed at different F0values was subjected to sensory evaluation and samples processed at F07 were judged superior with regard to various sensory attributes evaluated. Based on the manual and instrumental sensory evaluation, the optimum process parameters for the ready-to-serve shrimp curry were standardized. PRACTICAL APPLICATIONS The global demand for seafoods is increasing because of their high nutritive value and health benefits. Nowadays people prefer ready-to-serve products from fish and shellfish which can be stored for longer periods without refrigeration and preservatives. Thermally processed products meet these requirements. Conventional containers for canned products such as tin and aluminum have several disadvantages. Tin-free steel cans (TFS) have many advantages, such as easy-open ends, good coating performance, universal lacquer and aesthetic appearance. Tin-free steel cans were also found to be suitable for processing many varieties of fish products. This article describes the standardization of process parameters for the preparation of ready-to-serve shrimp curry in tin-free steel cans, which were microbiologically safe and acceptable with regard to various quality attributes. The standardized process can be modified and adopted by the fish processing industry to market similar ready-to-serve products in both domestic and export markets.

Canning of Rohu (Labeo rohita) in North Indian Style Curry Medium Using Polyester-coated Tin Free Steel Cans

Freshwater fish, rohu ( Labeo rohita) curry was prepared in a north Indian style, packed in polyestercoated tin free steel (TFS) cans in a 60:40 ratio (fish:curry) and thermal processed in a retort. Physical tests of the can such as double seam efficiency, lacquer integrity, sulphur resistance and food contact application showed that polyester-coated TFS cans can be used for canning fish products. F0 value of the product was 8.79 when the thermal processing was at 121°C for 46.42min, and cook value to achieve tenderness of the product was 102min. The processed product was found to be commercially sterile. The product was acceptable even after 6 months of storage at room temperature (28±2°C) and at 37°C with regard to all sensory attributes. Texture attributes such as hardness, chewiness, springiness and cohesiveness did not show marked variation in the samples stored at room temperature and at 37°C. There were no significant changes in chemical parameters during the storage period. The results showed that the polyester-coated TFS cans can be used for processing ready to serve fish products, which can be stored at room temperature for long periods.

Recent case histories of food product-metal container interactions using scanning electron microscopy-x-ray microanalysis.

Scanning electron microscopy (SEM) and x-ray microanalysis (EDS) were used to investigate stress corrosion cracking (SCC) in plain tinplate food cans, product discoloration, filiform corrosion, pitting/perforation corrosion, and loss of coating adhesion in enameled food cans. Intergranular SCC of uncoated tinplate occurred in canned pineapple juice. This is a rare occurrence in acid food products. The fracture developed in the can headspace only at the product line/metal interface by an interaction of the detinned metal surface with stress-inducing compounds in the product. Black discoloration of rice granules in the can headspace of a chicken and rice product was caused by the formation of metal sulfides. The source of the metal contamination was traced to metallic dirt in the coating on the tin-free-steel end. Blackening of light tan-colored olives and brine occurred after 1 year of storage in enameled tinplate containers as a result of pitting corrosion at the side seam weld. The cause of the pitting was a defective side seam stripe which failed to protect the weld. A perforation problem occurred at the score line of aluminum-tinplate bimetallic cans. The failure was caused by the high chloride content of the fruit product. Filiform corrosion resulted in perforations that occurred on the outside surfaces of two-piece tin-free steel cans packed with tuna. The cause of the corrosion was related to scratch defects in the exterior coating and the presence of chloride and sulfate cannery residues in the corroded areas. An enamel adhesion failure developed inside two-piece tin-free steel cans that contained mushrooms. Wrinkles in the coating which were introduced during can manufacture were cracked. The fractures were pathways for product-steel interaction which resulted in container failure.

Can Material Influence on the Performance of Rotating Cookers

ABSTRACTThe rotational performance of ETP (electro‐tin‐plated) and TFS (tin‐free‐steel) cans was studied in pilot and commercial cookers, and in a cooker simulator. TFS cans rotated less than ETP cans in both commercial and pilot cookers. Commercial cookers showed less can rotations than corresponding pilot scale experiments. The simulator predicted an exponential decay in lethality with decreased can rpm. Polymer coated cans conditioned the cooker surface and the extent depended on contact time. Heat transfer depended on can rotation and could be predicted with a suitable correlation. The correlation was used to predict lethality performance as well as exit temperature of processed foods.

Pitting Corrosion of the Aluminum Ends of Tin-Free Steel Cans

Abstract Bimetal cans, in which the body is made of tin-free steel (TFS) with easy-open ends of aluminum alloy, may be used to hold ion-supplementing drinks, juice, and the like. In such cases, the rest potential of the TFS in the contents of the can may be more noble than the pitting potential of the aluminum alloy, resulting in galvanic corrosion of the Al-alloy ends. Accordingly, studies were carried out on two methods of preventing such corrosion: (1) development of Al alloys having a higher (more noble) pitting potential, and (2) a technique for cladding with a sacrificially anodic material. Furthermore, in order to develop an aluminum alloy for the can ends that is resistant to pitting corrosion (i.e., has a more noble pitting potential), the Cu2+ ion method for rapidly measuring the pitting potential of the aluminum alloy has been developed and is being used to investigate the effects of various additive elements. This method has made it possible to develop an Al-Si-Cu-Mn alloy in which pitting cor...