Electrical impedance
Harker and Maindonald 1994 used electrical impedance measurements to look at the ripening of nectarine fruit. During ripening, the resistance of the cell wall and the vacuole declined and the capacitance of the membranes decreased. A higher resistance of the cell wall was observed in chilling-injured woolly fruits compared to normally ripened fruits. Varlan 1996 performed electrical impedance measurements on apples. She found a very high variance in the measurements. Although it was hard to...
Chapter 3
Professor I. M. Heinonen Department of Applied Chemistry and Microbiology PO Box 27 Tel 358 9 191 58224 Fax 358 9 191 58475 E-mail marina.heinonen helsinki.fi Tel 45 45 252598 Fax 45 45 884922 E-mail Stazione Sperimentale per l'Industria Fax 39 0521 771829 E-mail carloleo katamail.com Dr J. Aked 7 Whinnetts Way Pulloxhill Bedford MK45 5EX UK Tel 44 0 1525 718118 Fax 44 0 1525 718402 E-mail julia_aked hotmail.com
Mass and energy balances of tomato crops 541 Carbon
Basically, the production of biomass by a canopy relies on the net assimilation of atmospheric CO2, that is the balance between gross photosynthesis and respiration. It depends on the amount of available energy light and carbon substrate CO2 , and on the ability of the canopy to intercept light and assimilate CO2. In greenhouses, the assimilation of CO2 is not only important for crop growth, it interacts strongly with the composition of the atmosphere. The daily consump tion of carbon by a...
Behaviour of nutrients during processing lycopene
Data and information supplied in the scientific literature on lycopene degradation during common tomato processing, such as heat sterilisation, concentration by evaporation and dehydration, and also informationanddataon storageofprocessed tomato products, though sometimes some general conclusions and to the tests are either not well defined or donotcorrespondto thoseusedforindus-trial treatments, the results should be considered as being often unreliable. The data seem to suggest that...
Yield formation
Tomato has been a pioneer species for crop modelling. The formation of yield organ appearance, dry matter production and partitioning has been thoroughly studied and formalised by various approaches, again either mechanistic or empirical. The approach of fruit growth has been based on models of dry matter production. Water fluxes towards the fleshy tomato fruits around 95 water have only recently been studied and modelled. Different approaches of modelling biomass production have been developed...
Antioxidant Activity Of Vaccinium Empetrum Rubus
Apple showed strong antioxidant activity towards oxidation of methyl linoleate, although the apple extracts tested were low in total phenolics as well as ascorbic acid.4,54 In apple juice, vitamin C activity represented a minor fraction of the total antioxidant activity, with chlorogenic acid and phloretin glycosides as the major identifiable antioxidants.17,55 Dihydrochalcones such as phloretin glucosides and phloridzin amount to 5-223 mg kg-1 in apple juice, this content being greater than...
Citrus fruits
Citrus fruits are characteristic in containing high levels of ascorbic acid as well as relatively high levels of certain flavonoids. In their peel, citrus fruits also contain the unique glucaric and galactaric acid conjugates of hydroxycinnamic acids, mainly as feruloyl and p-coumaroyl conjugates at levels of 170-250mgkg-1 in oranges and 3-10 times less in lemons and grapefruits.39,40 It appears that the antioxidant potencies of these particular conjugates have not been systematically tested....
References Nmd
1 UNlECE, UN ECE Standard for Tomatoes FFV-36 , Working party on standardization of perishable produce and quality development, 56th session, Add. 14, Genova, UNlECE, 2000, 7 pp. 2 FAOlWHO, Codex Standard for Processing Tomato Concentrates CODEXSTAN 571981 , Rome, Codex Alimentarius Commission, 1981, 6 pp. 3 gary c, jones j w and tchAmitchiAn m, 'Crop modelling in horticulture state of the art', Scientia Hortic, 1998 74 3-20. 4 baiLLe a, 'The energy cycle', in Greenhouse Ecosystems, eds Enoch Z...
References Wgy
aked J and Henderson D 1999 'Respondingtothepesticidechallenge', FreshProduce J, 18 December,6. anon 1984 'Bitter pit development and controlinapples', DeciduousFruitGrower, 34, 61-3. bachem c w b, speckmann g-j, van der lindepcg, verheggenftm, huntmd, steffens j c and zabeau m 1994 inhibits enzymatic browning in potatotubers', Bio-Technology, 12, 1101-5. balls r c, gunn j s and starling a j 1982 TheNationalPotatoDamage Awareness Campaign, London, UK, PotatoMarketingBoard,32pp. barkai-golan r...
Stone fruits
Stone fruits encompass nectarines Prunus persica var. nucipersica , peaches Prunus persica L. , plums Prunus domestica , sweet cherries Prunus avium L. and sour cherries Prunus cerasus L. . In general, ascorbic acid is present in highest concentration in the fruit flesh, but the skin fraction contain larger amounts of phenolics than the flesh. Thus, in an investigation of phenolic compounds in nectarines, peaches and plums, the anthocyanins and flavonols the latter mainly as quercetin...
References Ips
carLin f and nguyen c 1999 Minimally Processed Produce - Microbiological Issues. Proceedings of the International Conference on Fresh-Cut Produce, 9-10 September 1999, Campden and Chorleywood Food Research Association, Chipping Campden, Gloucestershire. ccfh 1997 Hazard Analysis Critical Control Point HACCP System and Guidelines for its Application, Annex to CAC RCP-1 1969 , Rev. 3 1997 . Codex Committee on Food Hygiene, in Codex Alimentarius Commission Food Hygiene Basic Texts, Food and...
Areas of application yield prediction and crop management
Management can be defined as the sequence of three operations planning, implementation and control. The planning operation sets up the strategy which encompasses the goals assigned to the cropping system and the means to achieve these goals. Implementation performs the translation from the strategy into actions, while control ensures the proper applications of these actions by constantly monitoring the process and revising the mode of application of the action. The decision process leading to...
Quality criteria for fresh produce appearance texture flavour and aroma
The specific qualities required in fruits and vegetables will depend on their end-use and the selection of appropriate cultivars for particular products is of paramount importance. The quality of an individual product is also affected by its specific preharvest 'experience'. So, for example, the position of a fruit on the tree will determine its nutrient and water status and its exposure to environmental factors such as sunlight or pests and diseases. All these factors may ultimately influence...
Maintaining the postharvest quality of fruits and vegetables
J. Aked, Cranfield University at Silsoe 7.1 Introduction To achieve a high quality processed product, it is important that the raw materials used in the product are also of high quality. This chapter focuses on maintaining fresh produce quality prior to its processing. It assumes that the produce has been selected on the grounds of suitability for end-use and presents an overview of how the harvest quality may be maintained up to the point of processing or consumption. In section 7.2 the author...