FRUIT QUALITY ASSESSMENT

Alternative methods have been sought to both shorten and provide more objective evaluation of rot. Such methods have included identification and quantification of key indicator metabolites of mold (laccase and/or glycerol), bacterial (acetic acid), and native yeast (ethanol) activity. 

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Huyskens-Keil S and Schreiner M. 2004. Quality dynamics and quality assurance of fresh fruit and vegetables in pre- and postharvest. In Dris R and Jain S, editors. Production Practices and Quality Assessment of Food Crops. Dordrecht Kluwer Academic, pp. 101 119. 

The protocols presented here allow one to analyze the anthocyanins in fruit juices, natural colorants, and extracts from various anthocyanin sources. These profiles are useful for the identification of species, varieties, and for quality assessment of commercial products. They are also used to detect misbranding or adulteration of fruit products with other anthocyanin containing fruits, juices, or colorants. 

Senter SD, Callahan A (1990) Variability in the quantities of condensed tannins and other major phenols in peach fruit during maturation. J Food Sci 55 1585-1587, 1602 Sistrunk Wa (1985) Peach quality assessment fresh and processed. In Pattee HE (ed) Evaluation of quality of fruits and vegetables. AVI Publishing, Westport, CT, pp 1-46 Swain T (1965) The tannins. In Bonner J, Varner J (eds) Plant biochemistry. Academic Press, New York, pp 552-580... 

Lorente, D. et al. (2012) Recent advances and applications of hyperspectral imaging for fruit and vegetable quality assessment. Food Bioprocess Technol, 5 (4), 1121-1142. 

Noh HK, Lu RF. Hyperspectral laser-induced fluorescence imaging for assessing apple fruit quality. Postharvest Biol Technol 2007 43 193-201. 

One common objective of an LSMBS is to refine the estimates of actual exposure of consumers to ingredients or impurities in one or more products. For example, study results might be intended to determine a realistic human dietary exposure to pesticide residues in fresh fruits and vegetables. The advent of the Food Quality Protection Act of 1996 (FQPA) has produced an enhanced focus on the exposure of children to pesticides. A well-designed and implemented LSMBS would afford the opportunity to delineate better the exposure and risk to children and other population subgroups. The LSMBS would provide consumer-level data at or near the point of consumption, allowing the refined, relevant, and realistic assessments of dietary exposure. 

The accurate measurement of chlorophylls has importance for numerous reasons ranging from simple color considerations to medical research. The most practical of these is the assessment of fruit and vegetable color quality, as chlorophylls are known to degrade rapidly when subjected to thermal processing (Schwartz et al., 1981). However, interest has also been sparked by recent literature reports that point to the possible health benefits associated with chlorophyll consumption (Hartig and Bailey, 1998). 

Although there are only a limited number of methods that have been validated specifically for soft drinks, there are around 80 validated methods available for the analysis of fruit juices, most of which would work equally well for soft drinks. These methods are published in the International Fruit Juice Union (IFU) handbook of analytical procedures, which offers the best reference collection of methods for the analysis of fruit juices in the world, with new methods added on a regular basis (Anon, 2004a). The IFU s collection of analytical methods covers most of the main procedures required to assess the quality and authenticity of fruit juices and nectars. The methods are hsted on the IFU s website (http //www.ifu-fruitjuice.com) at the time of writing they cannot be purchased directly from there, but they can be obtained from the Swiss Fruit Union, Zug, and details of how to do this are given on the website. It is possible that at some time the methods will be made available directly from the website. 

As the flavour and odour of a soft drink or fruit juice are very important elements of a product they should be closely controlled. This is generally carried out by trained panellists who have been screened to ensure that they have an aptitude for this type of assessment they are often quality assurance personnel or workers from the factory. Sensory assessments should be carried out in surroundings where the panellists can concentrate without distractions. 

In a soft drink, or a fruit juice reconstituted from concentrate, the quality of the water is an essential element. Checking the water quality includes assessment to ensure that it does not contain any off-tastes or odour s. It also involves checking that any water-treatment processes have been effective and have not introduced defects into the water. The water should also be assessed to ensure that it does not contain materials that are likely to precipitate from the product on storage. Such precipitates are often called floes . 

In the analysis of fruit juices, it is important to determine the levels of the individual acids to assess authenticity and quality. A range of these acids can be determined using an enzyme-linked assays and these procedures have been collaboratively tested and published in the IFU compendium of methods (citric no. 22, isocitric no. 54, D-malic no. 64, L-malic no. 21 and D-and L-lactic acids no. 53). r-Biopharm now distributes the Boehringer Mannheim kits to assess the levels of these acids. Similar kits are available from other suppliers. 

Multidimensional techniques are regularly used in analytical assessments of measurement data relating to the levels of chemical elements in the quality control of animal and plant food products. Chemometric interpretations have been obtained for the following animal products meat and meat products [316-318], fish [319-321], seafood [25, 322-328], milk and dairy products [329-332] and honey [333-339]. Similar interpretations have been obtained for the following plant products rice [143], cereals [340], vegetables [140, 341-346], fruit and fruit preserves [347], tea [155, 348-350], coffee [13, 155, 351, 352], mushrooms [26], fruit juices [141], confectionery [21, 353], nuts [354], wine [355-358], beer [66, 359] and other alcoholic beverages [159, 360, 361]. 

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