Cultivars. Maturity Rutin. K-3-rut. Chlor. Ac. Bdlida. M. 10.48. 0.64. 44.84. SM. 12.73. 1.42. 39.76. G ... Ac., chloro- genic acid; M .... 20:115-125. 4. Ferreres F ...
Z Lebensm Unters Forsch (1994) 199:433-436
Zeitschrift for
9 Springer-Verlag 1994
Original paper
Influence of variety, maturity and processing on phenolic compounds of apricot juices and jams C r i s t i nG a a r c i a - V i g u e rPa el ,t e rB r i d l2e , F e d e r i c F o e r r e r e sF l ,r a n c i s cA o . Tomas-Barberanl 1Laboratorio Fitoqufmica, Departamento de Ciencia y Tecnologfade Alimentos, C. E. B. A. S. (CSIC), Apartado de Correos 4195, E-30080 Murcia, Spain 2 Institute of Food Research, Reading Laboratory, Earley Gate, Whiteknights Road, Reading, Berkshire, RG6 2EF, UK Received December 17, 1993; revised version May 4, 1994
Introduction E i n f l u gv o n S o r t e R , eifezustan ud n d B e h a n d l u nagu f d i ep h e n o l i s c h V e ne r b i n d u n gve onn A p r i k o s e n s l i f t e n u n dK o n f i t i i r e n The unambiguous characterization of plant-derived food products is important for establishing quality control parameters such as geographical and botanical origin, and A r r a y - D e t e k t iw o nu r d ez u r C h a r a k t e r i s i e mdnegr p h e n o l i - for detecting fraudulent mixtures. Flavonoid analysis has s c h e n V e r b i n d u n g einn F r t i c h t e nS, f i f t e nu n d K o n f i t t i r e n been used recently to study the origin of consumables such v o n A p r i k o s ebne n u t z tC. h l o r o g e n s ~ i du or em i n i e r tien a l l e n as wines [1, 2], honey [3, 4] and for the characterization of d r e i F o r m e n . Q u e r c e t i n - 3 - r u t e n ow s iadr d a s w i c h t i g s t e fruit juices and jams [ 5 - 1 2 ] . These compounds are very FlavonoidK , f i m p f e r o l - 3 - r u t e n owsai dr s t e t s i n k l e i n e n suitable as chemotaxonomic markers, since each plant M e n g e nn e b e n a n d e r e nG l y c o s i d e vn o r h a n d e nQ. u a n t i t a - species has a characteristic and specific flavonoid pattern t i v e U n t e r s c h i e dwe a r e nb e i 1 1 A p r i k o s e n s o r t iem n Zuge [13]. However, fruit variety, maturity and processing d e r R e i f u n gz u b e o b a c h t e na ,u c hb e i e i n i g e nP r o d u k t e nI .n techniques influence the phenolic composition of some a l l e nF f i l l e ng a b e s e i n g e m e i n s a m epsh e n o l i s c h ePsr o f i l . juices [14, 15]. D i e F l a v o n o i d ke o m m e n h a u p t s g c h l i ci hn d e r H a u t d e r To our knowledge, only a few reports exist concerning F r t i c h t ev o r , d e r G e s a m t p h e n o l g e hiasltt n i c h t v o m R e i apricot fruit phenolics [16] and information is lacking on f u n g s v e r l a ua fb h ~ n g i g . commercial products such as jams and juices made from these fruits. As part of our research programme studying A b s t r a cHt .i g h - p e r f o r m a nlci eq u i dc h r o m a t o g r a p hwyi t h flavonoids from fruit juices and jams to characterize these d i o d e - a r r adye t e c t i o w n a s u s e dt o c h a r a c t e r i zt he e p h e n o l i c products, we have investigated the phenolic profiles of p r o f i l eo f a p r i c o ft r u i t sj,u i c e sa n d j a m s .C h l o r o g e n iacc i d eleven apricot ( P r u n u s a r m e n i a c aL.) cultivars and dew a s t h e m a j o rp h e n o l i c o m p o u n dp r e s e n ti n a l l s a m p l e s . rived products to establish flavonoid markers for this fruit. Q u e r c e t i 3n - r u t i n o s i dwea s t h e m a i nf l a v o n o i adn d k a e m p The possible quantitative and qualitative changes in phef e r o l 3 - r u t i n o s i dwe a s p r e s e n ti n s m a l l e ra m o u n t sw i t h nolic composition according to variety, fruit maturity and t r a c e so f o t h e rq u e r c e t i ann d k a e m p f e r ogll y c o s i d e Q s .u a n industrial processing treatment are also considered.
Z u s a m m e n f a s s uEni gn e. H P L C - T e c h n i km i t D i o d e n -
t i t a t i v ed i f f e r e n c eisn p h e n o l i c w s e r e o b s e r v e di n e l e v e n a p r i c oft r u i tv a r i e t i east t h r e es t a g e so f m a t u r i t ya n d a l s oi n s o m e p r o c e s s e da p r i c o tp r o d u c t s .A c o m m o n p h e n o l i c p r o f i l ew a s o b s e r v e di n a l l c a s e s .T h e m a j o r p o r t i o no f t h e f l a v o n o i dosc c u r r e idn t h e s k i no f t h e f r u i ta n d t h e t o t a l p h e n o l i c o n t e n ot f a p r i c oft r u i t sh a d n o i n f l u e n coe v e rt h e s o f t e n i nbge h a v i o uor b s e r v e di n s o m ev a r i e t i e s .
C o r r e s p o n d et no c:C. e Garcia-Viguera
M a t e r i a lasn d m e t h o d s S a m p l e During s. 1990 eleven different cultivars of Spanish apricots were harvested at canning maturity from their typical production areas in Murcia. Manricio, Galtarrocha, Mayero and Valenciano, four early ripening cultivars, were harvested during the third week of May, the others during the second week of June. Seven of the cultivars were collected at three different maturity stages (Table 1). Five different commercial apricot jams were also studied, made from Bfilida cv, by manufacturers located in Murcia (Table 2, samples 1 and 2), Valladolid (samples 3 and 4) and Sevilla (sample 5). Two apricot juices (also Bfilida cv, from Murcia) and an apricot purse (from Bfilida cv flesh and skin, provided by a canning factory located in Murcia) were also included in this study.
434
T a b l e1. Changes in content of phenolic compounds of apricot fruits with maturity
T a b l 3. e Distribution of the main phenolic compounds of apricot fruits at canning maturity
Cultivars
Maturity
Rutin
K-3-rut
Chlor. Ac.
Cultivars
Bdlida
M SM G
10.48 12.73 26.92
0.64 1.42 3.36
44.84 39.76 64.87
Hojaico
M SM G
10.37 13.41 6.19
0.90 1.75 0.72
19.69 34.71 14.81
Colorao
M SM G
22.67 19.04 9.84
5.66 0.58 4.67
41.29 42.70 36.01
Pepitu
M SM G
5.65 6.77 9.42
0.10 0.75 0.68
19.42 19.19 29.00
Mauricio 38.4 Galtarrocha 24.0 Mayero 34.9 Valenciano 41.1 Bfilida 18.8 Hojaico 33.5 Colorao 32.6 Pepito 22.5 Velfizquez fino de agua 20.6 Moniqul 18.3 Real Fino 20.3
VelAzquez flno de agua
M SM G
4.59 10.27 7.12
1.91 0.61 0.38
15.79 54.60 28.36
Moniquf
M SM G
12.86 8.56 9.30
0.34 2.39 1.53
56.68 29.47 39.79
to the jams and pur~e. Phenolics in the available juices (200 ml) were exhaustively extracted with n-butanol (200 ml).
Real Fino
M SM G
12.07 13.48 26.34
1.04 0.93 3.57
46.39 42.56 67.86
S a m p l pe r e p a r a t i oButanol n. extracts were dried under reduced
Values are expressed as micrograms of phenolic compound per gram of fresh fruit: K-3-rut, kaempferol-3-rutinoside; Chlor. Ac., chlorogenic acid; M, mature; SM, semimature; G, green
Rutin
K-3-rut
Chlor. Ac. Total
10.0 4.1 9.6 8.0 1.1 3.0 8.1 0.4 8.6 0.5 1.7
51.6 71.9 55.5 50.9 80.1 63.5 59.3 77.1 70.8 81.2 78.0
7.39 12.26 15.71 5.89 55.96 30.96 69.62 25.17 22.29 69.80 59.50
Total values are micrograms of total phenolic compounds analysed per gram of fresh fruit. Rutin, kaempferol-3-rutinoside and chlorogenic acid are expressed as the percentage of total phenolic compounds analysed
pressure, redissolved in dilute HC1 (pH 2.0) and passed through a 40 x 2 cm column of Amberlite XAD-2 resin (Fluka), particle size 0.3-1.2 ram, pore diameter 90 A [21]. The adsorbed phenolic compounds were eluted with methanol and the eluate concentrated to 2 ml under reduced pressure.
H P L Ca n a l y s iPhenolic s. fractions (10 gl) were analysed by HPLC T a b l e2. Phenolic compounds in jams, juices and purre Sample
Rutin
K-3-rut
Chlor. Ac.
1 2 3 4 5 6
14.04 14.07 21.24 6.36 19.76 10.37
2.35 2.51 2.75 1.32 3.42 2.12
38.84 48.70 90.08 12.23 18.75 29.62
Juices 1 2
28.27 15.51
1.92 1.19
30.53 26.46
Purre
5.14
1.10
10.33
Jams
(Merck Hitachi L-6200 pump equipped with a photodiode array detector Merck Hitachi L-3000) using a Lichrochart 100 RP-18 column (12.5 • 0.4 cm, particle size 5 gm) (Merck, Darmstadt, Germany). Solvents used were (A) water-formic acid (95:5 v:v) and (B) methanol at a flow-rate of 1 ml/min. Linear gradient elution was used starting with 5% of B increasing to 30% B at 20 rain and then 50% B at 25 min. Chromatograms were recorded at 350 nm. All HPLC analyses were done in duplicate, the mean values being reported. Reproducibility was approx. _+ 6%.
I d e n t i f i c aat inodqn u a n t i f i c aot fipohne n o lci co m p o u nThe d s . phenolic
Values are expressed as micrograms of phenolic compound per gram of fresh fruit
compounds were identified using standard methods [22] including (a) UV spectroscopy in methanol before and after the addition of the classical shift reagents, (b) acid hydrolysis and identification of products and (c) chromatographic comparisons with authentic markers (rutin from Roth, Karlsruhe, Germany; Kaempferol 3-rutinoside isolated and identified previously from C a p p a rsipsi n o s[23]; a chlorogenic acid from Fluka, Switzerland). Phenolic compounds were quantified by peak area using authentic standards.
A p r i c omt a t u r i dt ye t e r m i n a t Cultivars ion. Bfilida, Hojaico, Colorao,
R e s u l t sa n d d i s c u s s i o n
Pepito, Velfizquez fino de agua and Moniqnf were harvested at three different maturity-stages (green, semimature and mature). Three different parameters were considered in order to assess the degree of maturity: c o l o uthe r , a* parameter in Hunter's Lab System [17], which gives a range of colour between green and red which is the most suitable for apricots according to Delwiche and Baumgardner [18]; f i r m n e sperformed s, with a Monet penetrometer [19] and e t h y l e n e p r o d u c t i[20]. on
E x t r a c t ioofpn h e n o lci co m p o u nFruits d s . with stones removed (200 g) were homogenized and exhaustively extracted with 400 ml of methanol-water (4: 1) for 18 h at room temperature and filtered. The filtrates were concentrated under reduced pressure to remove methanol and the phenolic compounds were completely extracted from the aqueous residue with n-butanol. The same extraction procedure was applied
A p r i c o pt h e n o l i c as n d t h e i rd i s t r i b u t i o n i n d i f f e r e nctu l t i v a r s T h e m a i n f l a v o n o i d in the apricot cultivars, c o l l e c t e d at canning maturity, was q u e r c e t i n 3-rutinoside; additionally, all cultivars c o n t a i n e d s m a l l e r a m o u n t s o f a q u e r c e t i n g l y c o s i d e (tentatively identified as q u e r c e t i n 3 - g l u c o s i d e ) and k a e m p f e r o l derivatives, o f these, only k a e m p f e r o l 3-rutinoside was p r e s e n t in sufficient a m o u n t to be quantified (Table 3). T h e s e results agree with p r e v i o u s l y r e p o r t e d data for other apricot cultivars [16] but differ f r o m results p u b l i s h e d on A m e r i c a n c a n n e d apricots w h e r e no k a e m p -
435 r e a s o n , i t i s i m p o r t a n tt o e v a l u a t et h e d i s t r i b u t i o no f p h e n o l i c sb e t w e e nt h e p e e l a n d t h e f l e s h .T h e r e s u l t si n T a b l e4 s h o wt h a tt h e m a j o rp o r t i o no f t h e f l a v o n o i drse s i d e i n t h e s k i n ;i n c o n t r a s th, o w e v e rc, h l o r o g e n iacc i di s m o s t l y l o c a t e di n t h e f l e s h . A l l t h e r e s u l t si n d i c a t et h a t q u a n t i t a t i vdei f f e r e n c eisn t h e p h e n o l i cc o n t e n to f a p r i c o t sd e p e n d o n t h e c u l t i v a r , m a t u r i t ys t a g e o f t h e f r u i t a n d t h e p a r t o f t h e f r u i tu s e d . H o w e v e r o, n e c o m m o nq u a l i t a t i vpeh e n o l i cH P L C p r o f i l e w a s d e t e c t e di n a l l c a s e s( F i g .1 ) .
A
_L
C h a n g eisnp h e n o l icco m p o s i t iw o ni t hp r o c e s s i n g C
H P L C a n a l y s e os f t h e p h e n o l i c o m p o u n d fsr o m p r o c e s s e d a p r i c o pt r o d u c t s( T a b l e2 ) w e r e i d e n t i c atlo t h o s eo b s e r v e d i n f r e s hf r u i t s a, n d a g a i ns h o w e dc h l o r o g e n iacc i da n d r u t i n I I I I a s t h e m a i n c o m p o u n d sa n d k a e m p f e r o l - 3 - r u t i n o siind e 5 15 25 35 min m u c h s m a l l e ra m o u n t s .N o d i f f e r e n c e w s ere found beF i g .1 . H P L Cp r o f i loef p h e n o l ci co m p o u nidnsa p r i c oBtf i l i dcav a t t w e e n t h e H P L C p h e n o l i c p r o f i l e s o f the commercial f u l l m a t u r i t yA:, c h l o r o g e naicci d ;B , q u e r c e t i n - 3 - r u t i nC o s, i d e ; j u i c e s a n d t h e c o m m e r c i ajla m s a v a i l a b l ei,n d i c a t i n gt h a t kaempferol-3-rutinoside t h e p r o c e s s i n gt r e a t m e n ti,n c l u d i n gc l a r i f i c a t i o nd ,i d n o t a f f e c tt h e q u a l i t a t i v pe h e n o l i cc o m p o s i t i o n( F i g . 1 ) . T h e o n l y f a c t o ra f f e c t i n gq u a n t i t a t i vdei f f e r e n c ew s as whether T a b l e4 . D i s t r i b u t oi of pn h e n o l ci co m p o u nidnsa p r i c of rt u i t s t h e p e e l e df r u i to r w h o l ef r u i tw a s u s e d i n t h e p r o c e s s . Cultivars Skin Rutin K - 3 - r u t C h l o rA. c T o t a l T h e s e a r c hf o r s i g n i f i c a nqt u a n t i t a t i vaen d q u a l i t a t i v e Mauricio S(+) 38.4 10.0 51.6 7.39 d i f f e r e n c ei sn t h e p h e n o l i cp a t t e r n so f t h e c u l t i v a r s t u d i e d S(-) 28.1 71.9 0.64 i s o f a d d i t i o n ai ln t e r e s tT. h e r o l eo f p h e n o l i c o m p o u n d as s i n h i b i t o r so f e n z y m e sr e s p o n s i b l oe f f r u i t s o f t e n i n gh a s G a l t a r r o c h aS ( + ) 24.0 4.1 71.9 12.26 S(-) 2.1 97.9 3.37 b e e nr e p o r t e d[ 2 6 - 2 9 ] ,f o r t h i sr e a s o nt h e s t u d yo f t h e t o t a l p h e n o l i cc o n t e n to f t h e d i f f e r e n vt a r i e t i e si s o f s p e c i a l Mayero S(+) 34.9 9.6 55.5 15.71 interestT . h e r e a r e w e l l - k n o w nd i f f e r e n c e isn t h e f r u i t S(-) 1.5 98.5 6.09 s o f t e n i n gb e h a v i o u ro f t h e t w o m a i n a p r i c o t c u l t i v a r s V a l e n c i a n oS ( + ) 41.1 8.0 50.9 5.89 u s e d b y t h e S p a n i s hi n d u s t r i e sT. h u s , c u l t i v a rB f l i d a i s S(-) 21.3 78.7 1.03 t h e m o s t i m p o r t a n ta p r i c o tu s e d i n t h e S p a n i s hc a n n i n g A s T a b l e3 : S ( + )f, r u i w t i t hs k i n S ; ( - ) ,f r u i w t i t h o ustk i n -; , t r a c e i n d u s t r y ( 9 0 % ) f o r a p r i c o t j u i c e a n d j a m p r o d u c t i o n amounts b e c a u s eo f i t s f l a v o u r ,t e x t u r ea n d p r i c e . H o w e v e r ,t h i s c u l t i v a ir s n o t s u i t a b l ef o r p r o c e s s i n ag s h a l v e si n s u c r o s e s y r u p ,a s i t s u f f e r ss o f t e n i n gO. n t h e o t h e rh a n d , c v R e a l f e r o ld e r i v a t i v ews e r e d e t e c t e d[ 2 4 ] .C h l o r o g e n iacc i d w a s F i n o i s u s e d w i t h o u ts o f t e n i n pg r o b l e m sf o r c a n n e dh a l v e s f o u n d i n a l l t h e s a m p l e s ,i n a g r e e m e n tw i t h p r e v i o u s i n s y r u po r w a t e r ,b u t i t s f l a v o u rc, o l o u ra n d p r i c em a k e i t f i n d i n g s[ 2 5 ] . u n s u i t a b l feo r j u i c e a n d j a m p r o d u c t i o n . T h e t o t a l a m o u n t o f p h e n o l i c c o m p o u n d sa n a l y s e d T h e p r e s e n ts t u d yr e v e a l e dn o s i g n i f i c a ndti f f e r e n c ei sn s h o w e d a t w e l v e f o l dv a r i a t i o n a c c o r d i n g t o c u l t i v a r t h e p h e n o l i cc o m p o s i t i o on f e i t h e rc u l t i v a rT. h u s i t w o u l d ( T a b l e3 ) . T h e f o u r e a r l y f r u i t i n gc u l t i v a r sc o n t a i n e dl e s s a p p e a rt h a tp h e n o l i cc o m p o s i t i oins n o t r e s p o n s i b lfeo r t h e t h a n 1 6 g g p h e n o l i c sp e r g r a m o f f r e s hf r u i t ,w h e r e a st h e d i f f e r e n c e fs o u n d i n s o f t e n i n gb e h a v i o u ro f t h e s e t w o r e m a i n i n gc u l t i v a r cs o n t a i n e d2 2 g g o r m o r e p h e n o l i c ps e r c u l t i v a r sa n d o t h e r p o s s i b l ec a u s a t i v ef a c t o r sn e e d t o b e g r a m o f f r e s hf r u i t ;t h e c u l t i v a r C s o l o r a oa n d M o n i q u fh a d i n v e s t i g a t eidn o r d e rt o e x p l a i nt h i s p h e n o m e n o n . t h e h i g h e s pt h e n o l i cl e v e l s I. n all s a m p l e sc, h l o r o g e n iacc i d w a s r e s p o n s i b l feo r a t l e a s t 5 0 % o f t h e t o t a l p h e n o l i c s A c k n o w l e d g eTmheeanut tsh. o rasr eg r a t e f tuol t h eS p a n i sCho m i s i d n I n t e r m i n i s t edreiC a li e n c iya T e c n o l o g( fAaL I 8 9 - 0 5 f4o3r)f i n a n c i a l c o s i d e r e dq, u e r c e t i n3 - r u t i n o s i dceo n t r i b u t e1d8 % o r m o r e , s u p p oor tft h i sw o r ka n da l s ot o D r .E R o m o j a rDor, .F .R i q u e l ma en d w h i l ek a e m p f e r o l - 3 - r u t i n o saicdceo u n t e df o r l e s st h a n 1 0 % o f t h e t o t a l p h e n o l i c ss t u d i e d .T h e q u a n t i t yo f p h e n o l i c G . M a r t i n eRze i n fao rd e t e r m i n a t ioofna sp r i c omt a t u r i st yt a g e s . c o m p o u n d si n t h e f r u i tv a r i e da c c o r d i n gt o m a t u r i t ys t a g e b u t i t w a s n o t p o s s i b l teo e s t a b l i s ah c o r r e l a t i obne t w e e nt h e f l a v o n o i dc o n t e n ta n d t h e d e g r e e o f m a t u r i t y( T a b l e 1 ) . H o w e v e r ,t h e q u a l i t a t i v pe h e n o l i cH P L C p r o f i l ew a s a l w a y s t h e s a m e r e g a r d l e sos f f r u i tm a t u r i t y . I n t h e i n d u s t r i atlr e a t m e n ot f a p r i c o tf r u i t st o p r o d u c e j u i c e s j, a m s o r f r u i th a l v e s ,a p r i c o t sa r e s o m e t i m e ps e e l e d w h i l ei n o t h e rc a s e st h e w h o l ef r u i ti s p r o c e s s e dF. o r t h i s
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