Mechanisms of deterioration of nutrients

The retention of flavor during freeze drying was studied with model systems. Mechanisms by which flavor retention phenomena is explained were developed and process conditions specified so that flavor retention is optimized. The literature is reviewed and results of studies of the flavor retention behavior of a number of real food products, including both liquid and solid foods are evaluated. Process parameters predicted by the mechanisms to be of greatest significance are freezing rate, initial solids content, and conditions which result in maintenance of sample structure. Flavor quality for the real food showed the same behavior relative to process conditions as predicted by the mechanisms based on model system studies

Evaluation of Shelf-Life Improvements of Wet Pack Clingstone Peaches Designed for Military Operation Rations by Addition of Calcium Salts

When available, wet pack peaches are produced by repackaging sliced and/or diced canned clingstone peaches into a 5-ounce MRE pouch, followed by a thermal process. In this study, wet pack diced peaches were processed in 5-ounce pouches using canned, fresh, and frozen peaches as the raw material. Calcium chloride was added at 0.0 or 0.5% (w/w) to the pouches. The pouches were then stored at 37°C for six months or 50°C for six weeks. The peaches were evaluated for texture, drained weight, pH, brix and sensory evaluations.The canned peaches were not significantly different from wet pack peaches processed using frozen and fresh peaches for overall liking when stored at 37°C for six months. Based on the inability of panelists to differentiate between peach types for overall liking, this study suggests that producers should continue to use canned clingstone peaches as the peach source for wet pack peaches.When calcium chloride was applied to wet pack peaches before thermal processing at 0.5% w/w, a significant increase was seen in the firmness of wet pack peaches after processing. Peaches treated with calcium chloride did not lose firmness as quickly when stored at 50°C for six weeks, but showed no difference in firmness loss rates when stored at 37°C for six months. Sensory analysis of the samples stored at 37°C for six months showed an improvement in firmness scores but a drastic decline in overall acceptance due to the impact of flavor scores.viMultiple levels of calcium chloride showed increased firming effects as the percentage of calcium chloride increased, with negative effects on flavor as the percentage increased. Flavor was not significantly affected by calcium chloride at 0.125% in sensory analysis. This study concludes that to optimize flavor and firmness of wet pack peaches, calcium chloride should only be added at a level up to 0.125%(w/w) that will result in a final pH ≥3.85

Shelf life studies on processed peaches

A series of experiments were conducted on the preservation of fresh peaches using freezing and heat (hot-filled packaging). In the first experiment, the effects of four calcium salts (calcium chloride, calcium lactate, calcium citrate, calcium phosphate) on the texture of processed peach slices were determined. Peach slices were immersed in solutions containing dissolved calcium salts at levels of 0.5, 1 and 2 % for 1 minute then stored at 4 ¡C for 3 days. Treatments with calcium salts were firmer than non calcium treated peach slices at all levels. Calcium lactate at 2 % level was best in terms of texture and overall appearance. In a second experiment set, effects of calcium salts at 3 % level was also determined for three different varieties of peaches (Autumn prince, Big Red, O\u27Henry) with a dipping time of 5 minutes. Increase in the level of calcium salts to 3 % did not generally improve the texture of peach slices. The effect of calcium salt combined with antibrowning agents on shelf life of peach slices was also studied. Peaches of Autumn Prince Variety were lye peeled, dipped in 1 % citric acid and were mixed with CaCl2 at the levels of 0, 0.5 and 1 % along with 0.5% citric acid and sodium erythorbate/ ascorbate each to prevent browning. In a final experiment, sugar was added to peaches in a 1:4 ratio with 0.5% sodium erythorbate or sodium ascorbate, 0.5% citric acid and CaCl2 then samples were frozen at the temperature of -20¡ C and stored for 48 weeks or first cooked at 93 ¡C (200 ¡F) and then mixed with CaCl2 at the same levels as frozen peaches followed by quick chilling and storage at room temperature for 32 weeks .Various shelf life parameters were evaluated including pH, color, total soluble solids (¡brix), water activity, puncture force (texture) and microbial count at 0, 8, 16, 24, 32, 48 weeks. The calcium treated samples generally had better quality than non calcium treated. Sodium erythorbate and sodium ascorbate were equally effective in maintaining the color (L*lightness) of frozen peach slices over the period of 48 weeks. Overall, processed peach slices were microbiologically stable over the storage period

The processing of unfermented peach juice

Investigators are generally convinced that the utilization of peaches in the production of juice would be desirable. Howerer, many investigators differ concerning the best type of juice to prepare and the varieties most desirable for its production. Some feel that the mere application of the basic principles involved in preparation and preservation of fruit juices now on the market will not produce a satisfactory product; others feel that the peach is too deficient in flavor and odor for juice production. Experiments which have furnished the data for this report were initiated in an attempt to find more conclusive evidence to answer these questions

Effect of Oxygen Scavenging Films and Modified Atmosphere on the Quality of Hot-Filled Freestone Peach Puree

The effect of pouch films with oxygen scavengers (OSs) and modified atmosphere on hot-filled Freestone Peach puree quality indices, such as colorimetric parameters (L*, a*, b*, ΔE*, Chroma, and hue angle), browning index (absorbance at 420 nm), soluble solids content (SSC, degrees Brix), pH, and titratable acidity (TA, % acid as Malic), were evaluated throughout 21-week accelerated storage at 35C/50% RH. Three multilayer pouch films, ultra-high-barrier with an OS (UHB-OS), ultra-high-barrier without an OS (UHB), and inorganic-barrier with OSs (IB-OS); and two internal atmospheric conditions (ambient air and nitrogen) were combined to produce six variable samples. Significant differences (p \u3c 0.05) in color values, L* (lightness), a* (redness), b* (yellowness) and Chroma (saturation) were only found between films, but not atmospheres. By the end of storage, ΔE* (total color difference) showed significant differences between films where Film UHB-OS showed the relative lowest color change (ΔE*=3.35c) followed by Film IB-OS (ΔE*=3.88b) and then Film UHB (ΔE*=6.73a). Although, based on trend line slopes of ΔL*, prediction of shelf life determined the most effective film as Film IB-OS (92 weeks), followed by Film UHB-OS (79 weeks) and Film UHB (53 weeks). Nitrogen had a lower ΔE* for the first 5 weeks, after which, color protection was based on film type, and nitrogen resulted in a lower hue angle and browning index throughout storage compared to ambient air demonstrating a protective effect. Suggested sucrose hydrolysis contributed reducing sugars for browning and increased SSC. Inconclusive results were found among pH and titratable acidity. This study demonstrated that OS films significantly extended peach puree shelf life were comparable to each other as well as nitrogen showed beneficial results over ambient air indicating prevention of oxygen-based degradative reactions

Research for the farmer : annual report of the Missouri Experiment Station, 1946-1947

Cover title

The Democratization of Food: Tin Cans and the Growth of the American Food Processing Industry, 1810-1940

This project draws from the history of technology and business history to determine how the transformation of the can manufacturing industry was coupled with changes in the food processing industry. Ultimately, American social and cultural change occurring in the late nineteenth century through the early twentieth century reshaped the contours of both food processing and can manufacturing. The tin can was the force that democratized food processing. The development of tin can manufacturing from a craft-based to a mass production industry between the years 1810 and 1930 occurred because of several important factors. The military use of tin cans during the American Civil War introduced and popularized the new food processing technology, but the price of canned food was beyond the reach of most Americans. It was a food source for the wealthy. The rapid development of can manufacturing technologies beginning in the 1870s through 1910s reduced the price of tin cans and made them affordable for most Americans. The deployment of technology, however, was non-uniform and canners and can manufacturers only adopted new machinery if it supported their overall business strategy. The consolidation of can-making began in the first few years of the twentieth century and by the 1920s resembled a duopoly. While consolidation and reorganization of the industry initially increased prices for canned food, competition and litigation by the federal government ensured price reductions and stability. In the early twentieth century canned food was becoming an increasingly large component of the American diet, and urbanization of American society generated additional demand. However, there was an undercurrent of suspicion associated with canned food among some consumers. The application of science, formation of a national trade association, and advertising all reassured American consumers about the safety of canned food and grew the market for these products. By the end of the 1920s, canned food was now a food processing technology demanded by Americans in ever increasing quantities and no longer the exclusive preserve of the wealthy. The ignoble and ubiquitous tin can was the technology which facilitated the growth of the food processing industry in nineteenth-century America. The development of the tin can as a container for food was regarded as nothing short of a revolutionary innovation in industrial America