Apple juice extracts

Figure 12. (A) Standard of dichloroacetyl-ETU (4.0 ng) (B) blank apple juice extract (C) apple juice extract spiked with 1 ppm ETU after extractive derivatiza-tion with DCAA. Conditions 6 X 2 mm i.d. glass column with 3% OV-330 on 80-100 mesh Chromosorb 750 flow rate, 30 mL/min helium oven, 200°C NP alkali flame ionization detector.

Figure 3. Anion exchange chromatogram with Particle Beam MS detection eluting with ammonium acetate buffer (selected ion monitoring, isobutane PCI) of daminozide (125 rjg) (top trace), compared to a sample of commercial apple juice extracted with a SAX SPE cartridge equivalent to 100 ppb daminozide contamination (bottom trace).

With this huge amount of concentrations it is possible to detect frauds like the addition of sugar, exhaustive enzymatic treatment (galacturonic acid), addition of citric acid or lemon juice (e.g. in apple juice), extraction of orange peel (phlorin) or the usage unripe Suits (quinic acid in apple juice). 

Bellion P, Hofmann T, Pool-Zobel BL, et al. Antioxidant effectiveness of phenolic apple juice extracts and their gut fermentation products in the human colon carcinoma cell line caco-2. / Agrio Food Chem. 2008 56(15) 6310-6317. 

Grape and apple juices usually contain all of the trace nutrients required by Saccharomjces for fermentation of sugars to alcohol. Other fmit and diluted honey, as well as barley malt and rice extract, frequendy need additions of nitrogen, phosphoms, and potassium compounds, together with some autolyzed yeast to faciUtate the yeast growth necessary for fermentation. Stimulation oiy4.cetobacter frequendy requires the addition of autolyzed... 

Chalcones and dihydrochalcones have been reported in a restricted number of foods (Robards and others 1999 Tomas-Barbcran and Clifford 2000). Chalconaringenin occurs in tomato skin, but the acid extraction conditions of the usual polyphenol analyses convert the chalcone to the corresponding flavanone (naringenin) in the tomato. The most common dihydrochalcones found in foods are phloretin glucoside (phloridzin) and phloretin xylogalactoside, which are characteristic of apples (see Table 2.2) and derived products such as apple juice, cider, and pomace (Robards and others 1999 Tomas-Barbcran and Clifford 2000). 

This method is also used to measure ex vivo low-density lipoprotein (LDL) oxidation. LDL is isolated fresh from blood samples, oxidation is initiated by Cu(II) or AAPH, and peroxidation of the lipid components is followed at 234 nm for conjugated dienes (Prior and others 2005). In this specific case the procedure can be used to assess the interaction of certain antioxidant compounds, such as vitamin E, carotenoids, and retinyl stearate, exerting a protective effect on LDL (Esterbauer and others 1989). Hence, Viana and others (1996) studied the in vitro antioxidative effects of an extract rich in flavonoids. Similarly, Pearson and others (1999) assessed the ability of compounds in apple juices and extracts from fresh apple to protect LDL. Wang and Goodman (1999) examined the antioxidant properties of 26 common dietary phenolic agents in an ex vivo LDL oxidation model. Salleh and others (2002) screened 12 edible plant extracts rich in polyphenols for their potential to inhibit oxidation of LDL in vitro. Gongalves and others (2004) observed that phenolic extracts from cherry inhibited LDL oxidation in vitro in a dose-dependent manner. Yildirin and others (2007) demonstrated that grapes inhibited oxidation of human LDL at a level comparable to wine. Coinu and others (2007) studied the antioxidant properties of extracts obtained from artichoke leaves and outer bracts measured on human oxidized LDL. Milde and others (2007) showed that many phenolics, as well as carotenoids, enhance resistance to LDL oxidation. 

Jo and others (2006) applied this assay to determine the antioxidant properties of methanolic extracts from Japanese apricot in chicken breast meat. Likewise, Pearson and others (1998) assessed two types of Japanese green tea from Japan and two of their active compounds, catechin and epicatechin, for their relative abilities to inhibit the oxidation of LDL. Also, Pearson and others (1999) assessed the ability of compounds in apple juices and extracts from fresh apple to protect LDL. Heinonen and others (1998b) observed that berry phenolics inhibited hexanal formation in oxidized human LDL. 

An extensive list of volatile compounds in apples and other fruits was included in a review by Nursten (222). White (223) reported that the principal components of the aroma of apples were alcohols (92% ) methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-l-propa-nol, 2-methyl-l-butanol, and 1-hexanol. The other constituents included 6% carbonyl compounds and 2% esters. Later, MacGregor et al. (224) tentatively identified 30 volatile components of McIntosh apple juice including four aldehydes, one ketone, 11 alcohols, 10 esters, and four fatty acids. The major organic volatiles in several different extractants of Delicious apple essence were identified and quantitatively estimated by Schultz et al. (225). They reported from sensory tests that low molecular weight alcohols contributed little to apple aroma. Flath et al. (226) identified... 

For phenolics in fruit by-products such as apple seed, peel, cortex, and pomace, an HPLC method was also utilized. Apple waste is considered a potential source of specialty chemicals (58,62), and its quantitative polyphenol profile may be useful in apple cultivars for classification and identification. Chlorogenic acid and coumaroylquinic acids and phloridzin are known to be major phenolics in apple juice (53). However, in contrast to apple polyphenolics, HPLC with a 70% aqueous acetone extract of apple seeds showed that phloridzin alone accounts for ca. 75% of the total apple seed polyphenolics (62). Besides phloridzin, 13 other phenolics were identified by gradient HPLC/PDA on LiChrospher 100 RP-18 from apple seed (62). The HPLC technique was also able to provide polyphenol profiles in the peel and cortex of the apple to be used to characterize apple cultivars by multivariate statistical techniques (63). Phenolic compounds in the epidermis zone, parenchyma zone, core zone, and seeds of French cider apple varieties are also determined by HPLC (56). Three successive solvent extractions (hexane, methanol, aqueous acetone), binary HPLC gradient using (a) aqueous acetic acid, 2.5%, v/v, and (b) acetonitrile fol-... 

Sometimes it is even important to look at the internal isotope ratios seen within a molecule such as malic acid in apple juice. Two groups, Isolab in Germany and Eurofms in France, found it was useful to look at the carbon isotope ratios at the Q and C4 positions of malic acid extracted from apple juice. This allowed them to detect the addition of synthetic L-malic acid to apple juice at much lower levels than would be possible by other means (Jamin el al., 2000). 

Enzymic juice extraction (apples, soft fruit, stone fruit)... 

Clarification apple juice Enzymic juice extraction... 

Clarification of apple juice. Inorganic membranes have been utilized in two ways in the production of apple juice. One is to clarify pressed or prefiltered apple juice and the other is to extract clarified apple juice directly from apple puree or pomace. Microfiltration of apple juice has been one of the most successful commercial applications of inorganic membranes. 

Juice from fmit which is mashed for juice extraction, e.g. apples, pears, pineapples, grapes, cherries, is produced by pressing. 

The reduction in viscosity of the juice extracted from such mashes facilitates the concentration and significantly increases the juice yield from apple mash by over 10% [12]. Especially important is the enzyme support for juice extraction from fmit containing large amounts of pectins, e.g. black currants, certain grapes and other fmit. 

Nogueira et al. (2005) evaluated the alcoholic fermentation of the aqueous extract of apple pomace. Apple juice, pomace extract, and pomace extract added with sucrose provided after fermentation 6.90%, 4.30%, and 7.30% ethanol, respectively. A fermentation yield of 60% was obtained when pomace extract was used, showing that it is a suitable substrate for alcohol production. 

We have applied a modified odor unit equation for evaluating aroma quality of the volatiles of Citrus sinensis OSBECK, ev. Shiroyanagi. Although the concept of odor units in flavor research was proposed by Rothe et al. (9) as a objective index of aroma quality, the concentration of individual components in a food (Fc in equation [1]) depends on the extraction efficiency of the essential oils. If the test sample is a solid, we can not calculate the exact concentration. Because the aroma oils, for example, may exist in different cells in the peels of citrus, we cannot take out only specified cells. It does not give a homogeneous concentration. Therefore, the odor units of individual aroma components in a food do not always give a constant value. Equation [1] should be applied to beverages such as apple juice, citrus juice, coffee, milk and so forth. The modified odor unit equation (75) for liquid and solid samples is shown as follows ... 

SPR is a representative physical phenomenon that is widely utilized for label-free characterization of molecules on thin metal films. The basic principle and operation of SPR has been described in more detail in several review articles [77, 78]. The reports on SPR-based immune sensors have steeply increased for detection of analytes with low molecular weights in recent years. SPR detection in microfluidic systems can provide various advantages. Immunoreactions are completed within a short time due to small sample volumes down to the nanolitre scale. Kim et al. developed a simple and versatile miniaturized SPR immunosensor enabling parallel analyses of multiple analytes [79]. Their SPR sensor was claimed to exhibit good stability and reusability for 40 cycles and more than 35 days. Feltis et al. demonstrated a low-cost handheld SPR-based immunosensor for the toxin Ricin [80]. Springer et al. reported a dispersion-free microfluidic system with a four-channel SPR sensor platform, which considerably improved the response time and sensitivity [81]. The sensor was able to detect short sequences of nucleic acids down to a femtomole level for 4 min. Waswa et al. demonstrated the immunological detection of E. coli 0157 H7 in milk, apple juice, and meat juice extracted from... 

Ethyl acetate is almost exclusively used for the extraction of procyanidins from aqueous solutions. Sometimes, crude extracts are directly partitioned using ethyl acetate, without prior elimination of lipids and pigments. This approach seems to be especially feasable in the analysis of beverages like wine [177], beer [74,178] and apple juice [179-180]. But also crude extracts of other matrices have been directly extracted using ethyl acetate... 

To separate neutral phenolics from phenolic acids in wine [190] and apple juice [179-180], an extraction with ethyl acetate at fixed pH values of seven and two has been proposed. Extraction efficiencies determined with standard solutions of (+)-catechin, (-)-epicatechin and procyanidin... 

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