Pigments of citrus, prune and cucurbit fruit seed oils were studied spectrophotometrically. The citrus fruits used were: orange (O), mandarin (M), bitter orange (BO) and lemon (L). The prunes used were apricot (A), peach (P) and plum (PL); while melon (M), watermelon (WM) and Winter squash (S) were the cucurbits. Absorption spectra and Lovibond color were studied for crude, refined and bleached oils. Cottonseed oil (CSO) was mixed with some of the previous oils in the crude state, then refined and bleached. Absorption spectra of the crude fruit seed oils revealed carotenoid pigments at 400, 425, 455 and 480 nm, chlorophyll at 610 and 670 nm and unknown pigments at 525, 570 and 595 nm. Refining did not remove these pigments, whereas bleaching eliminated them completely. In oil mixtures of CSO+A, CSO+M and CSO+S, interference occurred between gossypol ‘360 nm’ from CSO and the pigments of A, M and S seed oils. Refining the oil mixtures removed gossypol, but its effect on carotenoids, chlorophyll and unknown pigments was limited. Bleaching completely removed all these residual pigments. Lovibond color for all bleached oils was very low (0.2–2 yellow). The refined oils, except those containing Winter squash seed oil, were found to have an acceptable color (0.8–15 yellow). Results of the proposed process reveals the possibility of mixing crude edible oil with crude fruit seed oils, then processing the oil mixture by the conventional methods of refining and bleaching.

SummaryTo prevent or decrease colour fixation in cottonseed oil containing high level of phospholipids ('!yo), it wits treated before or after fixation with chemical and physical trcatmcnts using ethanolamine, degumming or sodium silicate. Treatment of cottonseed oil with ethanolamine at 4% of the oil before or aftcr fixation results in rcfined and bleached oils darker than the untreated oil. Carrying out dcgumming before fixation followed with ethanolamine at I % only of the oil improved the oil colour. Trcatmcnt of cottonseed oil with sodium silicate at 1 % of the oil before fixation results in superior rclincd and bleached oils than the untreated oils. ZusammenfassungBehandlung dcr Phospholipide zur Verhinderung odcr Mindcrung der Farbstoffbiiidung von Baumwollsaatijl Zur Verhinderung oder Minderung der Farbstoflbindung von phospholipidreichem (4%) Baumwollsaalol wurde dieses vor oder nach der Bindung chemischen oder physikalischen B e h a n d l u w p (Anwcndung von Ethanolamin, Entschleimung, Natriumsilicat) unterworfen. Die Behandlung des Oles mit 4% Ethanolamin vor oder nach der Farbstoffbindung fuhrt bei rafiinicrtcn und gebleichten Olen zu einer dunkleren Farbe als der von unbehandeltem 01. Entschlcimung vor der Farbstoffbindung und nachfolgende Behandlung mil nur 1 YO Ethanolamin verbessert die Olfarbc. Die Bchandlung von Baumwollsa~tol mil 1 ?O Natriumsilicat vor der Farbstoflbindung fuhrt zu bessercn raffinierten uiid gebleichtcn Olen als ohne Behandlung.

T h e c h a n g e s t h a t t a k e p l a c e in c o t t o n s e e d oilw h e n u s e d for f r y i n g " T a m e y a " w e r e i n v e s t i g a t e d . T h e a b s o r p t i o n s p e c t r a o f c o t t o n s e e d oil (CSO) a n d c o t t o n s e e d oil + c h l o r o p h y l l (CSO + Chl.) at w a v e l e n g t h r a n g e 5 0 0 -7 0 0 n m s h o w e d a s h a r p p e a k at 6 6 7 n m f o r CSO + Chl, w h i c h is c h a r a c t e ristic o f c h l o r o p h y l l . S t o r i n g CSO + C h l f o r o n e m o . r e s u l t e d in a s h i f t in t h e a b s o r p t i o n m a x i m a at 6 6 7 to 6 7 0 n m a n d t h e a p p e a r a n c e o f a b a n d at 6 1 0 n m , c h a r a c t e r i s t i c o f p h e o p h y t i n . H e a t i n g o f C S O + Chl at t h e f r y i n g t e m p e r a t u r e r e s u l t e d in t h e d i s a p p e a r a n c e o f all m a x i m a . T h e p e r o x i d e v a l u e o f CSO + C h l i n c r e a s e d d u e to s t o r a g e f o r o n e m o but d e c r e a s e d w h e n C S O + Chl w a s h e a t e d f o r o n e hr. T w o t y p e s o f T a m e y a w e r e i n v e s t i g a t e d , T a m e y a (A) w i t h p a r s l e y a n d T a m e y a (B) w i t h o u t p a r s l e y . T h e r e s u l t s r e v e a l t h a t T a m e y a (A) w h e n fried in CSO r e s u l t s in a n i n c r e a s e in t h e a b s o r p t i o n s p e ctra o f t h e oil at 6 7 0 n m a n d t h e s t a r t o f t h e a p p e a r a n c e o f a m i n o r p e a k at 6 1 0 n m . F u r t h e r h e a t i n g o f t h e oil r e s u l t i n g f r o m f r y i n g T a m e y a (A) s h o w s t h a t p h e o p h y t i n in t h e oil d i s a p p e a r s w i t h a n i n c r e a s e in h e a t i n g t i m e . H e a t i n g glyc e r o l + p h e o p h y t i n a l s o s h o w s t h e d i s a p p e a r a n c e o f p h e o p h y t i n p e a k s . F r y i n g o f T a m e y a A a n d B in C S O r e s u l t e d in a d e c r e a s e in t h e p e r o x i d e v a l u e o f t h e oil.

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