Differentiation, fruit

Figure 10.2 MDGC-MS differentiation between the enantiomers of theaspiranes in an aglycone fraction from puiple passion fruit DB5 pre-column (25 m X 0.25 mm i.d., 0.25 p.m film thickness canier gas He, 0.66 ml/min oven temperature, 60-300 °C at 10 °C/min with a final hold of 25 min) permethylated /3-cyclodextrin column (25 m X 0.25 mm i.d., 0.25 p.m film thickness canier gas He, 1.96 ml/min 80 °C isothermal for 20 min and then programmed to 220 °C at 2 °C/min). Reprinted from Journal of High Resolution Chromatography, 16, G. Full et al., MDGC- MS a powerful tool for enantioselective flavor analysis , pp. 642-644, 1993, with permission from Wiley-VCH.

Breithaupt, D.E., Wirt, U., and Bamedi, A., Differentiation between lutein monoester regioisomers and detection of lutein diesters from marigold flowers (Tagetes erecta L.) and several fruits by liquid chromatography-mass spectrometry, J. Agric. Food Chem. 50, 66, 2002. 

The pH differential method was described as a fast and convenient assay for the quantitation of monomeric anthocyanins by Giusti (2001). It was approved by the Association of OfQcial Analytical Chemists (AOAC) in 2005 as a standard method to evaluate total monomeric anthocyanin pigment content in fruit juices, beverages, natural colorants, and wines. The degradation index is the ratio between total and monomeric anthocyanins (Table 6.3.1). The content of total anthocyanins can be obtained by the single pH method and the monomeric anthocyanin by the pH differential method. ... 

Lee, J., Durst, R., and Wrolstad, R., AOAC official method 2005.02 total monomeric anthocyanin pigment content of fruit juices, beverages, natural colorants, and wines by the pH differential method, in Official Methods of Analysis of AOAC International, Horowitz, H., Ed., AOAC, Washington, D.C, 2005. 

Schmid and Richter (2000) showed that the premium prices for organic food were highest for fruit and vegetables (60% to 70%) and lowest for cheese (20%) and cereal products (31%). The premium prices for organic meat were 52% above conventional and for milk were 42%. The reason given by sales staff for the big price differential for fruit and vegetables was that these products cannot be stored for very long. The authors state that to promote sustained consumer... 

In the eastern United States apples of the Delicious variety treated 10 days prior to harvest with pure gamma isomer showed no trace of off-flavor at harvest time. Dusts and sprays applied to carrot seedlings produced no traces of off-flavor in the mature vegetables. Several tasters could not differentiate between peaches sprayed within a few days of harvest and check fruit. Celery in Florida sprayed twice, once within 6 weeks of harvest and once within 30 days of harvest, was canned and put through a severe series of tests. 

Consistent with the definition of terms adopted for the discussion in this series of papers of integral phases of the residue studies being conducted by the Division of Entomology, University of California Citrus Experiment Station (2, 13-15), the following distinctions are noted Residues may be specified as pretreatment, posttreatment, harvest, or ultimate. The latter refers to the residue on or in foodstuffs, whether fresh or processed, at the time of consumption (2, 13). The location of residues with reference to fruit parts may be extra-surface (external to the cuticle) or subsurface. Subsurface residues may be differentiated with reference to actual location as cuticular residues or specified intracarp residues. Residues in the cuticular layers or in any of the cellular structures or matrices are herein indicated as subsurface (penetrated) residues (2, 13). 

Rodrigo, M. J., B. Alquezar et al. (2006). Cloning and characterization of two 9-cw-epoxycarotenoid dioxygenase genes, differentially regulated during fruit maturation and under stress conditions, from orange (Citrus sinensis L. Osbeck). J. Exp. Bot. 57(3) 633-643. 

Differentiation can be defined as the process of specialisation in terms of shape and function. An example is cell differentiation in plants, animals and humans a young cell, which is initially multifunctional, gradually acquires one specific function and shape. Specialisation is a refinement that is expressed in terms of shape, scent and colour. For example, fruits ripen, leaves change colour in the autumn, the growth of a shoot ends in a terminal bud and seeds become dormant. The primary components are converted into secondary components such as phenols, vitamins, aromas, wax, and so on. Thus differentiation in this context has a broader meaning than only the formation of a new plant organ . 

Parameters for tree differentiation are autumn colours and bud formation (with equal bearing). Parameters for fruit differentiation are degree and hue of blush, yellow ground (background) colour, shape of fruit, sheen, starch conversion, differentiation score on crystallisation pictures and luminescence. 

Carotenoids and their biosynthetic precursors can be used as biomarkers of fruit product quality and adulteration of one product with another, such as fraudulent mixing of apricot jams and spreads with pumpkin extracts (Kurz and others 2008), and for differentiation of various pumpkins and squashes (Azevedo-Meleiro and Rodriguez-Amaya 2007). 

It was concluded from the data that the method is suitable for the differentiation between fruits and may help the detection of adulteration [241],... 

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