Agriculture and Food Science Research Collection
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- PublicationSynthesis and some Reactions of 2-Tosyloxyxchalcone Oxide(Society of Chemical Chemistry, 1962)
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- PublicationPrepacking and Shelf Life of Mushrooms(An Foras Talúntais, 1967)
;Mushrooms covered with the PVC film Resinite in a Hartmann Foodtainer dish had a shelf life of 5 to 7 days when stored at 15° to 21°C. Uncovered mushrooms had a shelf life of 2 to 4 days under similar conditions. Treatment of mushrooms with solutions of antioxidants followed by prepackaging with Resinite gave a shelf life of only 3 to 5 days. The shear press and reflectometer were found suitable for measuring texture and whiteness of mushrooms. Toughness of covered and uncovered mushrooms increased over a 5-day period. Uncovered mushrooms lost 31.6 percent of their original whiteness after 4 days while covered mushrooms lost 18.8 percent. The corresponding moisture losses were 68.3 and 10.8 percent. 482
- PublicationTexture studies on mushrooms(Wiley, 1969)Measurement of texture is a useful quality control test for mushrooms. Results of these studies suggest that texture differences in mushrooms may be divided into primary and secondary differences. the former refer to differences caused largely by variation in the dry matter content of mushrooms, the latter to differences caused by variation in the nature of the dry matter content. The shear press was used for measuring mushroom texture. Shearing mushrooms previously sliced with a household egg slicer gave more accurate results than shearing whole individual mushrooms. the relative precision of the shearing operation was the same for different weights of sample but increasing slice size had a slight positive effect on the shear press reading. Taste panels were capable of detecting texture differences in cooked mushrooms which were also detected by the shear press.
- PublicationAnalysis of Glasshouse Soils on a Volume Basis Without Drying the Sample(An Foras Talúntais, 1970)pH, K and SC readings from glasshouse soils were found to be almost independent of the moisture content provided the sample for analysis was taken on a volume basis. Cylindrical containers were most suitable for measuring volumes of soil for analyses. Different results were obtained when five operators carried out analyses for K on wet peat samples taken on a volume basis. The precision of all operators was excellent (CV ≤ 5.3%). The different results were due to variations in the technique of filling the container.
- PublicationSurvey of the Composition of Water Supplies Used in Glasshouses(An Foras Talúntais, 1970)
;Sample bottles and questionnaires were sent to 240 glasshouse growers in 24 counties. A response of 87% was obtained. The water samples were analysed for pH, Ca, Mg, Na, K, P, Mn, O, specific conductivity (SC) and total hardness. Information was obtained from the questionnaire on water source, storage, treatment, presence or absence of algae, use of a boiler for heating and sterilising, and type of feeding system used. Calcium and SC readings fluctuated most and, in general, supplies from wells were hard while those caught as 'roof rainwater' were very soft. The linear correlation between Ca contents and SC readings was 0.91, and the hardness of water was correctly predicted for 157 samples out of 197 by making an SC reading and converting it to ppm Ca using the regression line. Thirty-six percent of samples were obtained from wells, 29.4% from 'mains,' 14.7% from rivers and the remainder from combinations of these or other sources. Supplies which were stored were more likely to contain algae than those which were not. The hose system of feeding was used most frequently. Forty-five percent of growers used boilers, but of these less than one-fifth treated the water. Of the samples not treated 26.5% were classified as moderately hard, 21.0% as hard and 4.2% as extremely hard. 214
- PublicationA Complete Quality Control System(Institute of Food Science and Technology, 1971)
;Many people i the food industry feel that if they perform a test somewhere along the line the have performed their duty in relation to quality control and this is all that needs to be done. Any work done in quality control for maintaining a quality level is wasted unless a complete quality control system is used, i.e. that action results from the operation. A complete quality control system consists of a cycle which begins and ends with the buyers requirements or specifications (Fig.1). The specifications are the heart of the system and the purpose of quality control is to satisfy the buyers specifications at the least cost. The tests to be done on the product must be established and a sampling procedure decided upon. This is essential since it is usually not possible to test every unit of the product especially if the test is a destructive one. After testing, the results must be reported in such a way that they will lead to action if it is needed. 179
- PublicationThe Influence of Peat Soil on Crop Quality(Institute of Horticulture, 1971)Peat has a good potential for crop growth because of its many excellent physical properties, e.g., uniformity and water holding capacity. Much has been said about the high yields that may be obtained in peat, however, little information is available on quality, especially in comparison with crops grown in mineral soil. In Ireland peat is being used for the production of vegetables, fruit and flowers both outdoors and under glass and plastic. Experiments on carrot quality from peat and mineral soil began in 1969, and tests on tomatoes and strawberries were carried out in 1971. It is essential that quality should be studied because the time is fast approaching when the quality food product will be fully recognised and will command a premium price. In addition to the fresh market, processors also want top quality because they recognise that a high quality processed product requires top grade raw produce.
- PublicationSome aspects of the quality of carrots on different soil types(Wiley, 1971)
; ;Carrots are becoming an increasingly important crop in Ireland. High yields can be obtained, particularly on peat soils, but little information is available, as yet, on crop quality. Three carrot cultivars were grown in peat and mineral soil in 1969 and 1970 and samples of each were harvested three times in 1969 and twice in 1970 at 2-week intervals. Chemical analyses showed that cultivars grown in mineral soil had higher levels of carotene, alcohol insoluble solids (AIS) and dry matter (DM) in all harvests than those grown in peat; values for shear were also generally higher. Contents of reducing sugar for carrots from mineral soil were higher in 1969 but lower in 1970. Frozen samples from the 1969 experiments were cooked by a standard procedure and were presented to a taste panel. Those grown in mineral soil were rated higher for flavour and softer for texture than peat grown samples. Shear values also showed that both fresh and frozen carrots grown in peat were generally softer when raw, but firmer when cooked than those grown in mineral soils. No taste panels were carried out on samples in 1970, but shear values on cooked carrots showed that the unusual texture change observed in 1969 did not occur to the same extent in 1970. 405Scopus© Citations 2
- PublicationApplications of Quality Control to Liquid Feeding Systems and Testing of Peat Soil in Glasshouse(International Society for Horticultural Science, 1972)The importance of peat as a growing medium for glasshouse crops is well known. It is a standard medium to which all nutrients must be added and has excellent water holding capacity. Tomatoes are often grown in 15–20 cm of peat (shallow trough method) and considerable quantities of water and liquid feed are applied during the growing season, especially at times when there is a heavy demand because of good light conditions. It is easy, therefore, to underfeed or overfeed plants, especially since the depth of peat is so small and this could affect yield adversely. In addition, nutrition affects fruit quality so it is also important to ensure that all plants get the same amount of feed in order to maintain uniform high quality. Overfeeding plants also raises costs. The whole operation of feeding, watering and soil testing is similar to a production line in any manufacturing industry and lends itself readily to quality control methods.
- PublicationEffect of Water Consumption and Feeding Method on Soil Nutrient Levels and on Tomato Fruit Yield and Composition(An Foras Talúntais, 1972)Trickle feeding and irrigation of spring and autumn crop tomatoes grown in peat gave a lower soil pH and higher soil specific conductivity (SC) and K content than did feeding by hose or low-level sprayline methods. The use of hard water for making up feed and for irrigating gave a higher soil pH and SC than did moderately soft water. The trickle system gave the tallest plants in the autumn crop. In the spring crop plants were taller initially with the trickle system but the sprayline system gave the tallest plants later on. Hard water decreased height in both crops. Plants fed and irrigated with hard water yielded more marketable fruit in the spring crop than those treated with moderately soft water. The trickle system gave highest yields in both crops, and reduced the incidence of blossom-end rot in the spring crop. Values for fruit acidity, percentage soluble solids and K were lower in trickle-fed tomatoes, but water type had little effect on fruit composition.
- PublicationTomato Fruit FlavourWith rising standards of living consumers are becoming more aware of the food they eat and often criticise certain aspects of quality, such as flavour. This trend will continue and producers, wholesalers and retailers will have to become more flavour conscious in relation to the food they are selling. The complaint is often heard that today commercially produced tomatoes are not as good as the ones from the back garden. There may be some truth in this since tomatoes produced in the back garden usually receive individual attention from the home gardener. In commercial production it is not possible to give this individual attention and yields are much higher. However, if growing conditions and nutrition are good, high quality well flavoured fruit can be produced. Research is in progress at Kinsealy on factors influencing fruit flavour and at least one supermarket chain considers good flavour as one of the most important attributes of the tomatoes they sell. These examples show that flavour is not the neglected child that many people point the finger at and every effort is being made to include good flavour as an essential quality factor in addition to other attributes.
- PublicationQuality assessment of beetroot from storage(Wiley, 1973)
; ; ;Beetroot was stored in four different clamps until mid-May in two seasons and the quality of pickled sliced roots from the clamps was satisfactory, provided pickling was done by mid-April. The results indicated that the length of the storage period influenced quality to a greater extent than the type of clamp in which the roots were stored. Clamps with the roots covered with polythene were warmer than those with no polythene and in Season 2 this resulted in a loss of dry matter in roots in the former. Forced ventilation had little effect on the quality of the stored roots. Skin and flesh texture became tougher during the period of storage, but was not correlated with the texture after processing. Stored roots lost more pigment in Season 2 than in Season 1 and the colour of roots processed from storage on 26 May was still acceptable in Season 1 while in Season 2 the colour was not acceptable by the end of April. Flavour of roots processed from storage at any stage in Season 1 was acceptable, but those pickled after 29 April in Season 2 had an inferior flavour to those processed earlier. In both seasons storage diseases did not develop to any extent until April; they were more prevalent where clamps were fan-ventilated. 340
- PublicationFlavanoid Expoxides - XIII: Acid and Base Catalysed Reactions of 2'-Tostyloxychalcone epoxides. Mechanism of the Algar-Flynn-Oyamada Reaction(Elsevier, 1973)
;2'-Tosyloxychalcon.e epoxide (6a) on reaction with alkali gave flavonol (4a) while similar treatment of 6'-methoxy-2'-tosyloxychalcone·epoxide (6b), both at room temperature and. at the boiling point of the reaction medium, afforded 5-methoxyaurone (5b). The latter result indicates that an epoxide is not an intermediate in the production of flavanols from 2'-hydroxy-6'-methoxychalcone epoxides on treatment with alkaline hydrogen peroxide (AFO Reaction) at the higher temperature. Epoxide 6a on treatment with boron trifluoride etherate gave a mixture of flavanonol and flavonol while epoxide 6b gave.formyldesoxybenzoin (9) under similar conditions. 324Scopus© Citations 37
- PublicationThe Effects of Soil Management Systems on the Chemical Composition and Quality of Apples II. Cox's Orange Pippin and Red Jonathan Apples(John Wiley and Sons, Ltd., 1973)
; ;The quality of fruit of Cox's Orange Pippin and Red Jonathan from different soil management treatments was tested in 1969 and again in 1970. The range of tests included soluble solids, reducing sugar and acid contents, texture measurements and taste panel assessment. The non-cultivation treatment gave the highest yields and the quality of fruit of both cultivars from all treatments was acceptable. Grass improved the quality of Cox's Orange Pippin in 1969 but not in 1970. Cultivation gave higher soluble solids levels than non-cultivation for Red Jonathan in both seasons. There was no correlation between soluble solids content and taste panel response for either cultivar. However, solids levels of fruit from the different treatments tested were close together thus making it difficult for the panel to distinguish between samples. Soluble solids levels increased in fruit of Cox's Orange Pippin during storage at 1°C in 1969 but remained constant in 1970. Levels in Red Jonathan decreased in both seasons. Fruit of Cox's Orange Pippin became softer during storage in both seasons while fruit of Red Jonathan softened only in 1969. Acid levels for fruit of both cultivars from the different soil management treatments were not significantly different in either season. 263Scopus© Citations 4
- PublicationFrozen French fried mushroomsMushrooms were soaked in water or salt solution covered with batter, French fried and then blast frozen. Average weight loss/gain for the process for water soaked mushrooms (6 hr soak) was nil. The frozen product had a high quality shelf life of at least 9 months. Samples French fried and frozen within 2 hr of picking had a better flavour and softer texture than those kept at 18C and processed 24 hours later. French fried mushrooms that had been soaked in water or salt solution had a better flavour and texture than unsoaked ones. If the amount of batter used was increased an overall gain in mushroom weight for the process was obtained. However, product acceptability was adversely affected. Alternatively, the mushrooms can be soaked, coated with batter and then frozen. This results in a significant gain (up to 89% of initial weight) to the processor since the weight loss encountered at the frying stage is now passed on to the consumer. The quality of this product was tested after 4 months and was satisfactory.
- PublicationEffect of Processing on the Comparative Quality of Golden Delicious and Bramley's Seedling Apples(Elsevier, 1975)Processed Golden Delicious apples (GD) were compared with processed samples of Bramley’s Seedling apples (BS). Tasted panels found no significant difference between slices of the two cultivars, canned in syrup. Pies made with solid pack BS apples were significantly preferred to those made with solid pack GD apples. The GD samples lacked flavour and would not break down on cooking. Modification of the GD solid pack with a 2.5% malic acid solution before processing, improved flavour and texture and taste panels found no significant difference between pies made from modified GD apples and those made from solid pack BS apples. Treatment with malic acid did not have the same flavour and texture enhancing effect on frozen GD slices as it had on the solid pack slices and pies made with frozen BS apples were significantly preferred to those made with frozen malic acid treated GD apples.
- PublicationColour and its measurement in FoodsThe three main aspects of food sensory quality are appearance, sense of feel or texture and flavour. Of the three, appearance characteristics are probably the most important and the saying 'We eat with our eyes' is very true in most cases. Appearance factors can be subdivided into a number of areas: colour, gloss, shape, size, defects, oiliness, viscosity, etc. Colour is very important in food and is used to judge the quality, maturity and age after harvest of many foods. Leafy vegetables are expected to be a fresh green colour, carrots should be a deep orange, strawberries and meat a bright red, tomatoes yellow-red to red and pastries a nice golden brown . . Consumers often demand colours in foods that are not natural to the foods themselves and consumers in different countries have different colour preferences.
- PublicationA Laboratory Vacuum CoolerA laboratory apparatus for vacuum cooling up to 1 kg of horticultural produce at a time is described. The system consists of a vacuum pump and gauge, a water trap, and a cooling chamber fitted with thermocouples. Vacuum cooling tests on strawberries, mushrooms and lettuce showed that the apparatus worked satisfactorily and cooling rates were similar to those obtained with commercial cooking systems.
- PublicationA Laboratory Scale Liquid Nitrogen FreezerA laboratory scale liquid nitrogen freezer for food and other biological samples is described. In the apparatus, liquid nitrogen is forced under pressure through a sprayhead fitted to a plastic pipe. The sample for freezing is inserted into the pipe under the liquid nitrogen sprays. Freezing times for strawberries, mushrooms and tomato slices were 6, 4 and 2 min respectively with this system.
- PublicationTechnical note: Food texture-modification of the shear press using a strain gauge system(Wiley, 1975)
;The shear press is an instrument for measuring food texture (Kramer, Burkhardt &Rogers, 1951). The original model was introduced in 1950 and it was later modified for electrical indicating and recording (Decker et al., 1957). A new more versatile and precise model was introduced in 1956 (Kramer & Twigg, 1958). In this instrument force is measured by a maximum-reading dial gauge fitted across the vertical diameter of a proving ring. If time-force texture graphs are required, a transducer can be fitted across the ring in place of the dial gauge to give a print-out on a strip chart as the sample is tested. This note reports an alternative and relatively cheap system for converting a dial reading shear press to a recording model. Strain gauges are attached to the proving ring and the electrical output is amplified and is recorded on a strip chart in the form of a texturegram. The dial gauge remains in place to indicate maximum deflection. The system is simple and easy to construct. 245