Rapid determination of malic and citric acid in apple juice by high performance liquid chromatography

Ascorbic Acid Degradation in a Model Apple Juice System and in Apple Juice during Ultraviolet Processing and Storage

“…The model system, unless otherwise stated, consisted of a 0.5% (w/v) solution of malic acid at pH 3.3. Values for malic acid concentration and pH were selected based on compositional surveys of apples (Mattick and Moyer 1983; Lee and Wrolstad 1988; Jeuring and others 1979). Solution pH was adjusted using 1 N NaOH or HCl.…”

Recent applications of high pressure liquid chromatography* to food analysis

“…It is not possible to include all the recently developed methods but the following examples will illustrate the almost universal applicability of HPLC: the sterols testosterone in meat (Stan & Hohls, 1979) and coumestrol in soyabeans (Lookhart, Jones & Finney, 1978), Amadori compounds in model Maillard browning systems (Takeoka, 1979), amines in wines (Subden ef al., 1979), fish products (Schmidtlein, 1979) and chocolate (Ingles, Tindale & Gallimore, 1978), total and available lysine (Peterson & Warthesen, 1979), methionine in fortified foods (OKeefe & Warthesen, 1978) and cysteine in fruit (Saetre & Rabenstein, 1978), isothiocyanates in rapeseed (Maheshwari et al, 1979) and in vegetables (Mullin, 1978), glycoalkaloids in potatoes (Walter, Purcell & McCollum, 1979), esters of hydroxy cinnamic and tartaric acids in grapes (Ong & Nagel, 1978), amides and phenols in coffee beans (Hunziker & Miserez, 1979;Folstar et al, 1979) and organic acids in cranberries (Coppola, Conrad & Cotler, 1978), wines (Symonds, 1978) and apple juice (Jeuring et al, 1979).…”

“…Other applications cover a very wide range of foods and include beverages (Bricout, 1978;Qureshi, Prentice & Burger, 1979;Jeuring, 1979), liquorice (Beasley, Ziegler and Bell, 1979), peppers (Verzele, Mussche & Qureshi, 1979), capsaicin (Iwai et al, 1979;Sticker, Soldati & Joshi, 1978) and citrus and other volatile oils (Latz & Ernes, 1978;Ross, 1978;Rousseff & Fisher, 1978). The xanthine alkaloids, particularly caffeine, have provided the subject matter for a number of papers.…”

“…Other mycotoxins which have received attention in recent years include zearalenone (Frischkorn, Frischkorn & Ohst, 1978;Hunt, Bourdon & Crosby, 1978a;Scott et al, 1978;Ware & Thorpe, 1978;Moeller & Josefsson, 1978;Diebold, Karny & Zare, 1979a;Josefsson & Moeller, 1979), rubratoxin (Unger & Hayes, 1978), patulin (Hunt et al, 1978aLeuenberger, Gauch & Baumgartner, 1978;Stray, 1978;Woidich et al, 1978a;Brackett & Marth, 1979), xanthomegnin (Stack, Brown & Eppley, 1978) and territrems, mycotoxins of Aspergillus terreus (Ling, Yang & Huancy, 1979).…”

“…The technique is also employed to study individual synthetic dyes in more detail such as the separation of the colourants E l 10 and E l 11 (Frede, 1978) or as a criterion of purity since chemically similar impurities may have toxicological effects (e.g. Jones, Hoar & Sellings, 1978).…”