Essential Elements and Cadmium and Lead in Fresh, Canned, and Frozen Green Beans (Phaseolus vulgaris L.)

Sixteen essential elements, cadmium and lead were determined in fresh, canned, and frozen green beans (Phaseolus vulgaris L.). Samples were taken during processing to determine where changes in element content occurred. Canned green beans contained lower concentrations of calcium, copper, iron, magnesium, manganese, phosphorus, potassium, and zinc, but had higher amounts of chloride, nickel, and sodium than fresh beans. No change in silicon was observed. Iron, phosphorus and potassium were lower in frozen than in fresh green beans, but calcium, sodium and zinc were higher. There was no change in chloride, copper, magnesium, manganese and silicon due to freezing. Element retention ranged from 51 - 100% for canned and from 73 - 171% for frozen green beans.     

Essential Elements and Cadmium and Lead in Fresh and Canned Peas (Pisum sativum L.)

Sixteen essential elements along with cadmium and lead were determined in fresh and canned peas (Pisum sarivum L.). Samples were taken during the canning process to determine where changes in element content occurred. The concentration of each sample was compared statistically to other samples taken at different stages of the process. Canned peas contained significantly lower concentrations of calcium, copper, iron, magnesium, manganese, phosphorus, potassium, silicon, and zinc than fresh peas. As sodium chloride was added during the canning process, higher concentrations of chloride and sodium were found in the canned product. A 100g serving of drained canned peas supplied less than 11% of the RDAs or of the estimated safe and adequate daily dietary intakes except for chloride and sodium. Retention of all elements, except chloride and sodium, ranged from 24–86%.     

Nutritional value of some canned tomato juice and concentrates

Fresh tomatoes, juice and concentrate were analysed chemically. The canned tomato products were not a good source of vitamin C, but their niacin content was higher than that of the fresh tomatoes. Thiamin was not affected by the canning process, but riboflavin was, and vitamin A was slightly affected. Nine elements: Ca, Cu, Fe, Mg, Mn, Ni, K, Na and Zn, were determined in the fresh tomato and its products, but Pb was found only in the final products.     

Lycopene content and antioxidant activity of fresh and processed tomatoes and in vitro bioavailability of lycopene

BACKGROUND: Lycopene, a phytochemical, has attracted a great deal of interest over the past few years. This has triggered research on the biological properties of lycopene and on the numerous factors that control these properties. Therefore, the aim of the study was to investigate lycopene content and antioxidant activity of fresh, sun‐dried and canned tomatoes. In addition, in vitro bioavailability of lycopene was determined. RESULTS: Lycopene contents of fresh, sun‐dried and canned tomatoes were found to be 1.74, 5.51 and 3.55 mg 100 g^?1, respectively, on a fresh wet basis. The highest lycopene bioavailability was obtained for sun‐dried tomatoes (58.05%) and this was followed by fresh (28.67%) and canned tomatoes (21.83%). Fresh tomatoes showed the highest antioxidant activity against ABTS radical oxidation. This was followed by sun‐dried tomatoes and canned tomatoes. The inhibition effect of intestinal dialysates of the samples on ABTS radical oxidation was between 51.34% and 92.96%. CONCLUSION: Maintenance antioxidant activity and existence of lycopene following an in vitro digestion process were the main findings, which might contribute forthcoming studies in this scientific field. Copyright © 2007 Society of Chemical Industry     

THE INFLUENCE OF THE FIRMNESS OF RAW TOMATOES ON THE PHYSICAL, CHEMICAL AND SENSORY CHARACTERISTICS OF CANNED PRODUCTS

The effects of firmness of raw tomatoes on selected quality characteristics of canned products was the primary objective of this study. Firm fruits, as sorted with Holme's Vibratory Sorter, were found to be significantly (P≤ .05) higher in drained weight, Agtron E-5 color readings, total acidity, sodium hexametaphosphate-soluble, and sodium hydroxide-soluble pectic substances, and lower in pH, soluble solids, soluble solids/acid ratio, and water soluble pectin than soft and unsorted fruits. In determining the sensory quality, firm fruits were superior in flavor, texture, and overall quality but inferior in color compared to soft and unsorted fruits. This investigation revealed that sorting fresh tomatoes with a vibratory sorter and canning only the firm fruits had a positive impact on improving the quality of canned products.     

Nutritional comparison of fresh,frozen, and canned fruits and vegetables II. Vitamin A and carotenoids,vitamin E,minerals and fiber

In this second part of our review, we examine the literature for changes in carotenoids, vitamin E, minerals, and fiber due to processing, storage, and cooking of fresh, frozen, and canned fruits and vegetables. While inconsistencies in methodology and reporting methods complicate interpretation of the data, the results show that these nutrients are generally similar in comparable fresh and processed products. The higher levels of carotenoids typically found in canned as compared to fresh products may be attributed to either reporting results on a wet rather than dry weight basis, greater extractability, or differences in cultivars. There are relatively few studies on processing, storage, and cooking effects on vitamin E in fruits and vegetables. Further research is needed to understand nutritional changes in those few fruits and vegetables rich in vitamin E, such as tomatoes. Minerals and fiber are generally stable to processing, storage, and cooking, but may be lost in peeling and other removal steps during processing. Mineral uptake (e.g., calcium) or addition (e.g., sodium) during processing can change the natural mineral composition of a product. Sodium concerns in canned food can be addressed by choosing products with no salt added. Since nutrient content varies considerably by commodity, cultivar, and postharvest treatments, inclusion of a wide variety of fruits and vegetables in the diet is encouraged. Copyright © 2007 Society of Chemical Industry     

Chemical studies of some plant wastes from Ghana

The proximate composition of sodium, potassium, calcium, phosphorus and iron levels of the peels and trunk from banana and plantain plants and cocoa husk are reported. The samples were all characterised by high moisture content ranging from 78 g/100 g ripe plantain peel to 94 g/100 g for fresh plantain trunk. The peels and trunk of plantain and banana plants were poor sources of phosphorus and sodium but rich in iron and potassium. Plantain trunk contained 5 g of potassium per 100 g of dry sample. Because of their high potassium content the peels of banana fruit and the trunk of banana and plantain plants are recommended as additional raw materials for indigenous soap making in Ghana.     

Essential Elements,Cadmium, and Lead in Raw and Pasteurized Cow and Goat Milk

Fifteen essential elements plus cadmium and lead were determined in raw and pasteurized cow and goat milks by atomic absorption spectrophotometry. When results were compared on a wet weight basis, there were no significant differences between the raw and pasteurized milks except for cobalt, iron, and lead in goat milk. When copper in goat milk was expressed on a dry weight basis, there was a significant difference between raw and pasteurized milk. There were significantly higher amounts of cobalt, copper, iron, lead, magnesium, and phosphorus, wet weight basis, in pasteurized goat milk than in pasteurized cow milk. Significantly more nickel and sodium were in pasteurized cow milk. No difference in the content of chloride, calcium, potassium, and zinc was significant between the two milks. When dry weights of the two milks were compared, statistical differences were the same, except there was significantly more calcium and potassium in pasteurized cow milk than in pasteurized goat milk and there were no significant differences in the content of lead and phosphorus between the two milks.Percentages of the established and estimated recommended daily allowances show both cow and goat milk to be excellent sources of calcium, phosphorus, and potassium and fair sources of iron, magnesium, and sodium.     

HPLC Analysis of Organic Acids and Sugars in Tomato Juice

The effect of break temperature on changes in organic acids and sugars in canned juices made from VF145-7879 and UC 82B tomatoes was investigated by HPLC. Oxalic, citric, galacturonic, malic and pyrrol- idonecarboxylic acids were shown to be present in the canned juices. Oxalic and galacturonic acids decreased as the break temperature increased. Fructose was present in slightly higher amounts than glucose. Break temperature did not cause significant changes in sugar content of the canned juices made from UC 82B tomatoes.     

Yields, Proximate Composition and Mineral Content of Finfish and Shellfish

Yields of edible flesh, proximate composition, and mineral content were determined in two samplings of six finfish and four shellfish from the Chesapeake Bay region. Although there was considerable variation, most species have high protein (above 20%), low fat (less than 5%) and are relatively good sources of macrominerals, including calcium, phosphorus, magnesium and potassium. The ratio of sodium to potassium ranged from 1:4 to 1:15. These species, particularly the shellfish, are excellent sources of the trace elements, including copper, iron, zinc and manganese. Minerals are very high in certain shellfish.     

Proximate composition, minerals and vitamins in selected canned vegetables

The proximate composition, and mineral and vitamin contents of canned white asparagus, whole peeled tomatoes, mushrooms and lentils were studied. The composition of the canned products did not vary during the harvest season, but calcium, sodium and potassium contents depended on the hardness of the water, added sodium chloride, and, in the case of lentils and mushrooms, the use of potassium metabisulfite or sulfur dioxide during soaking. After the canning process, the studied vegetables retained at least 89% protein, 65% carbohydrate and between 47% and 95% of the vitamins B₁, B₂, B₆ and C (dry weight basis, DW) versus the respective raw materials. The canned mushrooms and lentils did not lose crude fiber and whole peeled tomatoes and white asparagus retained 73% (DW) crude fiber.     

红树莓海藻酸钙凝胶硬化工艺优化及其罐头品质分析

以红树莓为主要原料,通过响应面分析法建立海藻酸钙凝胶硬化红树莓果粒工艺模型,确定最佳工艺条件为海藻酸钠1.24%、抽空时间Ⅰ 41 min、氯化钙0.32%、抽空时间Ⅱ 31 min,此条件下红树莓果粒硬度为451.18 g,感官分数为90.23分。红树莓、蓝莓和草莓罐头品质比较分析表明:各罐头V_C含量由高至低依次为草莓、红树莓、蓝莓罐头,差异显著(p<0.05);红树莓和蓝莓罐头总酚含量差异不显著(p>0.05),但显著高于草莓罐头(p<0.05);红树莓罐头V_C和总酚保留率高于其它罐头;红树莓罐头还原糖、总酸和可溶性固形物含量均显著低于其它罐头(p<0.05)。经硬化的红树莓罐头更有效地保留了其营养成分。     

FREEZE PEELING IMPROVES QUALITY OF TOMATOES

SUMMARY— A process of peeling tomatoes using low temperature-short time freezing was perfected. Liquid nitrogen (BP-196°C was used as the refrigerant for freezing the skin and only a thin layer of cells just beneath the skin. The fruit was immediately thawed, after which the skin was quickly and easily removed from the fruit. Liquid nitrogen-peeled samples were evaluated for loss of peel and trim, as well as lycopene and carotene in the peeling process and these losses compared with samples peeled in boiling water. The losses in peel and trim were reduced by approximately 50%, and significantly less lycopene was lost by nitrogen peeling. The peel and trim of fall tomatoes had a greater amount of lycopene and carotene than spring tomatoes. The nitrogen-peeled samples were canned without additives, with sodium chloride and with calcium chloride added and compared with samples peeled with boiling water. There was a decrease in the percentage of broken fruit in the canned tomatoes peeled by liquid nitrogen. Titratable acidity and °Brix were higher and pH was lower in these samples. Color of the homogenized canned product was not statistically different; however, the nitrogen-peeled tomatoes had a better visual color. The calcium chloride added-nitrogen-peeled samples possessed a higher degree of firmness than the comparably treated boiling-water-peeled samples, indicating that the nitrogen-peeled tomatoes utilized the added calcium to a greater extent in firming.     

Chemical Composition of Saskatoon Berries (Amelanchier alnifolia Nutt.)

Saskatoon berries, Amelanchier alnifolia, have been analyzed for moisture, soluble solids, protein, fat, fiber, Ca, P, S, K, Mg, Na, Fe, Mn, Cu, Zn, Ba, Mo, Al, and carotene content. The composition of saskatoon berries was compared to that of blueberries (Vaccinium sp.). There were significantly higher amounts of protein, fat, fiber, calcium, magnesium, manganese, barium, and aluminum, and lower contents of phosphorus and sulfur in Saskatoon berries than in blueberries. No significant difference in iron, zinc, sodium and carotene content was found between saskatoons and the other fruit. On a dry weight basis, saskatoons contained less sugars than blueberries. Although bioavailability of the minerals was not determined, saskatoons appear to be an excellent source of manganese, magnesium and iron and a relatively good source of calcium, potassium, copper, and carotene.     

Changes in pectin methylesterification and accumulation of methanol during production of diced tomatoes

The degree of methylesterification (DM) of the pectins in tomatoes affects the firmness of diced products and the consistency of juices. We examined the changes in DM that occur during commercial production of diced tomatoes packed in tomato juice. Ripe processing tomatoes contained low amounts of free methanol (<20 μg g fresh weight⁻¹) and had a high degree of pectin methylesterification (60%). During production of diced tomatoes, the level of free methanol increased while the degree of pectin methylesterification decreased. Diced tomatoes canned in tomato juice contained about 200 μg methanol g fresh weight⁻¹, and had a DM of about 35% in the dice and less than 25% in the juice. Similar results were obtained for aseptically processed bulk packed tomatoes. Low-temperature blanching of canned diced tomatoes caused additional pectin de-esterification in the diced tomatoes and improved firmness. Heating of the diced tomatoes prior to mixing with topping juice, first to temperatures that maximally activate PME then to temperatures that inactivate PME and other enzymes, is proposed as a way to both improve dice firmness and preserve the consistency of the topping juice.     

Essential Elements in Tomatoes and Fresh and Canned Tomato Juice

Sixteen essential elements along with cadmium and lead were determined in tomatoes (Lycopersicon esculentum L.) and fresh and canned tomato juice by atomic absorption spectrophotometry. Samples were taken during the canning process to determine where changes in element content occurred. The concentration of each sample was compared statistically to other samples taken at different stages of the process. RDAs and estimated safe and adequate daily dietary intake values as well as percent retention values were calculated. Retention of all elements, except chloride and sodium, ranged from 91–160%.     

Mineral Element Composition of Bovine Spleen and Separated Spleen Components

The content of 15 essential elements in whole beef spleens and in mechanically separated spleen pulp (MSS) and its connective tissue residue was determined by atomic absorption spectrophotometry. There were greater amounts of potassium, phosphorus, sodium, iron, and magnesium in MSS than in the whole spleen. Zinc was more concentrated in the residue. Upon cooking, larger quantities of potassium, phosphorus, sodium, iron, magnesium, and tin were noted in MSS than in the raw samples. Content of potassium, phosphorus, sodium, tin and zinc also increased in cooked whole spleen samples as compared to uncooked samples. Silicon content decreased with cooking in both the MSS and whole spleen samples.     

Tin and Iron Content of Canned and Bottled Foods

The tin and iron content of 14 different types of canned foods and of 5 different types of bottled foods were determined. No tin was detected in most bottled foods, but tin was detected in all canned foods. Storage of foods on the shelf for 4 months or in open cans in the refrigerator for 1 wk resulted in increased amounts of tin and iron in some of the canned foods. Those foods which were packed in totally lacquered cans accumulated little tin or iron during storage; those foods which were packed in unlacquered or partially lacquered cans generally accumulated significant amounts of iron and tin during storage. The tin content of the canned foods was not statistically correlated to the pH of the foods.     

面粉中的强化铁在面包加工中化学形式的变化

将各种铁源加到面粉中,制成面包,测定其中铁存在的化学形式,研究面包生产过程中发酵、焙烤、贮藏对铁化学形式的影响。发现除乙二胺四乙酸铁钠外,添加其他铁源,经焙烤制成面包后,最终都产生了大量不溶性铁。由此可见,在面粉中强化铁剂制成面包,最终产品中的铁化学形式,并不取决于起始所加铁源的不同,焙烤加工对铁的化学形式的影响更为重要。乙二胺四乙酸铁钠为面包中适宜的铁强化剂。     

Nutritional content of fresh and canned peaches

BACKGROUND: The objective of this study was to assess whether canned peaches could deliver nutrient levels comparable to fresh peaches. Fresh freestone peaches, fresh cling peaches and canned cling peaches were analyzed for vitamins A, C and E, folate, antioxidants, total phenolics and total carotenoids to assess how these nutrients were affected by the canning process and whether storage further changed these components. RESULTS: The vitamins and phytochemicals measured in this study were found to be present in canned cling peaches versus fresh freestone at statistically significantly higher levels (vitamin C, antioxidants and folate); higher but not statistically different levels (vitamin A); or lower, but not statistically different levels (vitamin E, total phenolics and total carotenoids). There were no statistically significant changes in nutrient content during storage for 3 months. CONCLUSIONS: The nutritional content of canned peaches has been shown in this study to be comparable to that of fresh peaches. There were no statistically significant decreases in those nutritional parameters measured in this study between fresh freestone peaches and canned cling peaches. Vitamins A and E along with total carotenoids decrease immediately upon processing, but appear to stabilize after the processing step, showing minimal additional changes upon storage for 3 months. This study shows that canned peaches can provide comparable nutrient levels to the consumer as fresh peaches, meaning that consumers can enjoy peaches year round without worrying about loss of nutrients in their diet. © 2012 Society of Chemical Industry