III. EVALUATION OF COLDPRESSED FLORIDA LEMON OIL AND LEMON

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1 32 FLORIDA STATE HORTICULTURAL SOCIETY, 958 of the three packs contanng juce from each of the 42 lemon selectons. The effect of stor age for one year at -8 F. on the flavor of these concentrates has not yet been determned. Persons who evaluated the ntal flavor were requested to ndcate f the products had a typcal lemon flavor, and f any off-flavors were detectable. Four of the lemonades, n ther opnon, were acceptable. A slghtly dfferent flavor character was ob taned n the concentrates to whch the folded ol of lemon was added than that found n those contanng coldpressed lemon ol; how ever, ths slght dfference n flavor was not consdered sgnfcant. All of the concentrates for lemonade, except those from two of the lemon selectons, when judged on the bass of flavor were acceptable snce they had a typcal lemon flavor and no off-flavors were detectable. As prevously men toned, the concentrate prepared from Selec ton No. was excessvely astrngent and btter because of excessve pressure used durng the extracton and fnshng of ths juce. An offflavor was detectable n the sweetened juce made from the Meyer lemons, Selecton A, and ths undesrable flavor was ntensfed when coldpressed Meyer ol of lemon was added to the sweetened juce. Ths confrmed prevous reports from several commercal plants that certan precautons have to be taken, n usng the juce from Meyer lemons n frozen concen trate for lemonade, to prevent a non-typcal lemon flavor n the product. Snce ths offflavor may be removed from the juce by vacuum concentraton, t s apparently caused by a trace of Meyer lemon ol whch becomes mxed wth the juce durng extracton. A con centrate for lemonade that was acceptable, snce t dd not contan any detectable offflavor, was prepared from concentrated Meyer lemon juce to whch lemon ol of good qualty had been added. Also, the objectonable flavor n sweetened Meyer lemon juce was masked when ether folded ol of lemon or coldpressed ol, prepared from lemons other than the Meyer, was added to the sweetened juce. However, f the off-flavor was ntense, t mght be mpossble to mask t completely. The 42 raw lemon juces and the 42 concen trates for lemonade contanng the same folded lemon ol, were examned for mcro bologcal content. The total plate counts were found to be very low for the lemon juces, rangng from 00 to 23,000 per mlllter on orange serum agar. The concentrates for lem onade, examned mmedately after prepara ton and pror to freezng, showed counts from 00 to 5,700. Gas producng organsms, chefly yeasts, whch could cause fermentaton f the lemon juces or concentrates were dluted wth water, were found n some of the products. No colform bactera or streptococc were found n any of the lemon juce or concentrate samples. LITERATURE CITED. Anon. Almanac of the frozen foods ndustry. Quck Frozen Foods Annual Yearbook, p Bartholomew, E. T. and W. B. Snclar. The lemon frut. Unv. Calf. Press, Berkeley and Los Angeles. 63 pp Batchelor, L. D. and H. J. Webber. The Ctrus In dustry. Vol. II. Producton of the crop. Unv. Calf. Press, Berkeley and Los Angeles. 933 pp Cole, G. M. Concentrates for lemonade. Food Technol. 9: Florda Department of Agrculture, Tallahassee, Florda. Florda's lme and lemon ndustry. Bulletn No pp. 6. Ford, H. W. Is there a place for lemons n Florda? Florda State Hort. Soc. Proc. 67: Unted States Department of Agrculture, Agrcultural Marketng Servce, Washngton, D. C. Unted States Stan dards for Grades of Frozen Concentrate for Lemonade. Effectve February, 958. III. EVALUATION OF COLDPRESSED FLORIDA LEMON OIL AND LEMON BIOFLAVONOIDS J. W. Kesterson and R. Hendrckson Florda Ctrus Experment Staton Lake Alfred Lemon ol of acceptable qualty s currently sellng at $4.00 per pound; at ths prce the gross return on a box of frut would amount to Florda Agrcultural Experment Staton Journal Seres, No. 88. approxmately 75 cents to $.00 for the ol alone. Thus, t s apparent that qualty of ol s an mportant consderaton n the selecton of varetes. In some years the proceeds from the ol mght spell the dfference between proft and loss. From the standpont of market acceptance as an essental ol, lemon ol should meet cer tan requrements ncludng those specfed n

2 KESTERSON AND HENDRICKSON: LEMON OIL 33 the Unted States Pharmocopoea. It should have a hgh aldehyde content and from a flavor standpont t should be a rch full-boded ol wth a defnte ctral effect. Moreover, for a proftable operaton the varety selected for plantng should gve a hgh yeld of ol. Expermental Procedure Ol samples were extracted n the Ctrus Experment Staton Plot Plant as descrbed n Part II of ths seres. The ol emulson from the juce extractor was collected and passed through a model #35 Deluxe Grade Super Juce Fnsher wth manual dscharge adjust ment. A screen wth nch perforatons and head clearance set at to nch was used to remove gross partcles of pulp. The lqud dscharged from the fnsher was collected n a 50-gallon stanless steel tank and allowed to stand 3 to 5 hours so that the ol emulson would rse to the top of the tank. The bottom 80 per cent of the tank contents were dscharged to the dran and the ol emul son retaned. The emulson was then passed over an 80-mesh shaker screen to remove fne partcles of pulp. The emulson was then put through a laboratory model Sharpes Super Table I. The physcal and chemcal propertes of coldpressed lemon ol. Selec ton 'o. Specfc gravty 25 C/25 C Refractve ndex 20 n ndex of 07. dstllate n20 D Dfference Optcal rotaton a25 D Optcal rotaton of 07. dstllate a25 a D Dfference Aldehyde content 7. evapora tve resdue 7. U. V. Spectrum mu log E 0.25g 00 cc * /4J / A B 0.B

3 34 FLORIDA STATE HORTICULTURAL SOCIETY, 958 Centrfuge wth a bowl speed of 25,000 r.p.m. n order to break the emulson and free the ol. The resdue from the centrfuge bowl was collected and mxed wth the fne pulp par tcles obtaned from the shaker screen. To ths mxture standard eel was then added, and the mxture subjected to hydraulc pressure for the recovery of an ol emulson, whch n turn was centrfuged to obtan the free ol phase. The ol obtaned from the emulson and bowl cake were combned to gve the fnshed coldpressed lemon ol sample. Results and Dscusson of Results The physcal and chemcal propertes of the samples of coldpressed lemon ols pro duced are presented n Table. Freeze Damage. -Ols 36 and 37 were produced from frut that had been exposed to a one-nght freeze December. Ols 38, 39, and 40 were produced from frut that had been exposed to freezes the nghts of Dec ember and 2. The data presented n Table ndcated that these freezes had no detrmental effect on the physcal and chem cal characterstcs of the ol. Jqutoua PbM* c G«I./G*. Ol Fg. 2. Scatter dagram to show the relatonshp of alde hyde content to the aqueous phase. I Ol Recovery from Centrfuge Bowl Cake. When the emulson was dffcult to break, the percentage of ol recovered from the bowl Aqu«ou* Phoe > 0*./C»l. Ol Fg. 3. Scatter dagram to show the relatonshp of yeld of ol to aqueous phase. Fg.. aldehyde Yeld = Lb. OU/Ton rrult &# Scatter dagram to show the relatonshp between content and yeld of ol. cake exceeded 6 or 7 per cent. Consequently, t was an easy matter to pck out those lemon selectons that processed easly. Aldehyde Content, Yeld, and Quantty of Aqueous Phase. Although each sample con ssted of a dfferent selecton, the ol qualty was strongly assocated wth amount of ol obtaned (yeld) compared to amount of aque ous phase (a relatvely constant amount n these runs) used n processng. When yeld of ol was low, a low proporton of ol to aqueous phase resulted (Fg. 3), and a low aldehyde content was found n the ol (Fg. ). Ths relatonshp may also be expressed nversely as a low aldehyde content of ol asso-

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5 36 FLORIDA STATE HORTICULTURAL SOCIETY, 958 On ths bass t appears that frut whch produces a hgh yeld of ol wll also produce an ol whch s hgh n aldehyde content. Ths relatonshp between aldehyde content and yeld has never been prevously reported. Further work wll be necessary before ths re latonshp can defntely be establshed. Ol Evaluaton. The physcal and chemcal propertes used as a crteron of purty for coldpressed lemon ol are shown n Table 2 and may be used to evaluate the qualty of the ol samples prepared from the 42 lemon selectons. In Table 3 the aldehyde content n order of ncreasng value s presented for 42 samples Table». Yela of ol n pounds per ton of frut In order of ncreasng value for *2 lots Lbs. ol/ ton frut of Florda lemon ol. (A) () (2) 5 - (6) (3) (24) - (25) 9 - (32) 4 - (34) - 8 B Selecton No. 0 - (7) - (8) (22) (29) - (36) (30) ( (3) - Table 3. Aldehyde content n order of ncreasng value for 42 lots of Florda lemon ol. ( ) - Sample numbers n parentheses dd not nset the specfcatons of the Unted States Pharmacopoea. Aldehyde - % Sample No. Table 5. The 0 best lots of Florda lemon ol on the bass of aldehyde content and yeld of ol. Aldehyde content Yeld of ol (A) (8) (2) (22) - (32) - (34) () (24) - (28) - (36) 40 (6) (29) (3) - (7) Selecton B* 8* 2 7* * 26* 33 38* 2* 0 37* no. Lbs/ton frut Selecton no. B* 8* * 2* 37* 9 27* 33* 26* B 8 (30) (25) (3) of lemon ol. The yeld of ol n pounds per ton of frut n order of ncreasng value s presented n Table 4 for these same ols. It can be seen from these tables that 8 of the lemon selectons studed yelded an ol whch faled to meet the specfcatons of the Unted States Pharmacopoea. Twenty-four of the lemons evaluated gave an ol that met the specfcatons outlned n Table 2. The 0 best lots of Florda lemon ol se lected from these 24 on the bass of aldehyde content and yeld of ol are summarzed n Table 5. From the standpont of aldehyde * - Sample number appears twce n ths table. content the 0 best lemons are as follows: Sclan, Bearss #, "M" Lemon, Bearss #2, Italan, Ctrus Experment Staton III Row G-5, Vllafranca, Des 4 Sason, Harvey #2, and Sexton #2. From the standpont of ol yeld the 0 best lemons are as follows: Scl an, Bearss #, Bearss #2, Des 4 Sason, Sexton #2, Correga, "M" Lemon, Vllafranca, Italan, and Moreland. These same 42 lemon ol selectons were submtted to a large essental ol company for an organoleptc evaluaton. From a careful organoleptcal examnaton the ol samples were evaluated as follows: Sample #26 - Italan - Ths s a rch full boded ol wth a defnte ctral effect, and we feel that ths represents the best commercal type submtted.

6 KESTERSON AND HENDRICKSON: LEMON OIL 37 Sample #B Sclan Whle ths sample showed a hgher ctral content by analy ss than #26, t was less pronounced on organoleptcal examnaton. We would classfy ths ol as our second choce. We would then group sample #8 Bearss #, sample # Bearss #2, sample #27-"M" lemon, and sample #3-Vllafranca as representng our thrd choce. Lemon Boflavonods Boflavonod s a term commonly used to descrbe a group of flavanone compounds that possess bologcal actvty. These substances are prevalent n ctrus fruts. They mantan the normal condtons n the walls of the small blood vessels (5) and are consdered to have a physologcal effect on the human system that parallels that of a vtamn. Ctrus boflavonod dervatves are a chem cal possblty and lemon boflavonod com plex s currently sellng for $9.00 per pound. It s possble that a recent renewal of nterest n these compounds could make them an m portant factor n the producton of lemons. Therefore, the prncpal purpose of ths study was to determne the potental quantty of bo flavonods that could be recovered from lemons. Expermental Procedure The lemons were processed through a Food Machnery In-lne juce extractor. A repre sentatve sample of the ejected peel and rag was then commnuted n a Ftzpatrck commnuter to pass a one-half nch screen. A 4,000 gram sample of ths commnuted peel was m medately processed for ts boflavonod con tent. In each case 6,000 ml. of water was added to 4,000 grams per peel. Ths mass was contnually strred for one hour at ph 0.5 to 0.8, whch was obtaned by small addtons of calcum hydroxde. It was strred an addtonal 5 mnutes at ph.0, after whch the mass was hydraulcally pressed and the clear press lquor adjusted to ph 5.0 wth concentrated hydrochlorc acd. The lquor pressed out was weghed and a 250 ml. por ton concentrated fve tmes and stored at 40 F. for later chromatographc and ultravolet analyss. The remander of the expressed and neutralzed press lquor was processed to re cover a crude hesperdn or boflavonod com plex. Ths was accomplshed by heatng the lquor to 55 C. and strrng for two hours wth 30 grams of flter eel. The sample was fltered the followng day, the resdue was dred at 05 C. and ground to pass a 28-mesh screen. Ths fnal product was analyzed by the Davs () procedure. A few samples of the crude hesperdn or boflavonod complex were further analyzed under vsble and ultravolet lght. Selecton Nos., 8, 9, 25, 26, 28, 30, 37, and A were dssolved at varous concentratons n 0.2 N sodum hydroxde and dluted wth 90 per cent dethylene glycol and 4 N alkal as n makng the Davs test. The samples were analyzed 30 mnutes later n a Beckman Model B spectrophotometer at varous wave lengths usng a 0 mm. cell. Certan samples of the crude boflavonod complex were analyzed n the ultravolet regon. Ths was accomplshed by dssolvng 00 mg. of the dred product n 25 ml. of dmethylformamde to whch one drop of gla cal acetc acd has been added. After one hour, one ml. was dluted to 25 ml. wth more dmethylformamde, and the soluton analyzed n a Beckman DU Quartz spectrophotometer usng a 0 mm. cell.. The concentrated lemon extracts stored at 40 F. were chromatographed n a prelmnary fashon wth the ad of p-ntro-anlne dazo as a chromogenc spray. Results and Dscusson of Results The extracton data accumulated from the alkalne extracton of the 42 commnuted lemon peel samples are shown n Table 6. The lemon selectons have been lsted n accord ance wth hesperdn yeld obtaned. It wll be noted that there s no correlaton between hesperdn yeld from a lemon selecton and the grams of calcum hydroxde or volume of hydrochlorc acd used. The selectons yeld ng the hghest quantty of crude hesperdn or boflavonod extract often had the lowest per cent of actual hesperdn, by vrtue of a hgher quantty of ballast mpurtes. The var ance of the per cent hesperdn n the crude hesperdn s also shown. In ths same table are the degree of Brx (acd corrected refractometer readng) and per cent acd of the lemon juce for each lemon selecton. No correlaton

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8 - KESTERSON AND HENDRICKSON: LEMON OIL 39 or trends exsts between these fgures and hesperdn yeld. Although the 42 lemon selectons have been arranged accordng to yeld of hesperdn whch was determned by the non-specfc Davs test, t should be understood that hesper dn yeld from oranges s related to maturty (2). Thus t s qute possble that f the samples were pcked n a dfferent order, or at a dfferent degree of maturty, that the order of arrangement of selectons would be dfferent. It was further noted that the best yelds of hesperdn from the lemons were no better than those obtaned from oranges. Ths, of course, could be due to the maturty of the samples. If the hesperdn of lemons s the only boflavonod present of commercal mportance, then lemons would not appear to have a compettve advantage over oranges. When the concentrated neutralzed boflavo nod fltrate samples stored at 40 F. were chromatographed, t was found that they all were very smlar except for Selectons 25 and A. These selectons dd not show a typcal oa 0. ; / - / / / I / j j * \ \. \ \ V ' /^\ \ * 5 * T» Fg. 5. Comparson of three lemon boflavonod extracts n the ultra-volet regon usng a DU Quartz spectrophotometer, 0 mm. cell and dssolvng samples n dmethylformamde as a 0.06 per cent of soluton. hesperdn spot when sprayed wth p-ntroa BUf l«vas«u EsUMta anlne dazo. It was expected that there mght be sharp dfferences among the 42 samples, but ths was not the case. In an attempt to fnd other sgnfcant df ferences between the lemon selectons, cer tan samples of the solated crude hesperdn were dssolved at varous concentratons n dmethylformamde, colormetrcally developed by Davs test, and analyzed n a Beckman, Model B spectrophotometer usng 0 mm. cells. P^gure 4 graphcally shows dfferences among samples that are more than just con centraton dfferences. From ths fgure t can be seen that Selecton Nos., 37, A, 26, 8, and 9 closely resemble one another and ap pear to dffer markedly only n concentraton. Selecton Nos. 25, 30, and 28 were dfferent n appearance by more than just concentra ton level. Selecton 25, whch s most unlke the others, contaned a very low concentraton of hesperdn. Fg. 4. Comparson of boflavonod extracts by Davs test at varous wave lengths. Dluton of samples, 8, 9, 25, 26, 28, 30, 37, and A was respectvely 3, 4, 4, 24, 4, 0, 0, 2, and 4 grams per 500 ml. of 0.2 N sodum hydroxde. In another attempt to fnd sgnfcant df ferences between lemon selectons, some of the crude hesperdn samples were dssolved n dmethylformamde and compared n the ultravolet regon usng the DU Quartz spec trophotometer and 0 mm. cells. These results

9 40 FLORIDA STATE HORTICULTURAL SOCIETY, 958 are shown n Fgure 5. It wll be noted that each selecton had typcal maxmum absorp ton peaks at 285 mu. as does hesperdn and closely resembled each other except for con centraton level. Dscusson The physcal and chemcal propertes of samples of coldpressed lemon ol prepared from 42 lemon selectons have been determn ed. It was shown that the December freeze had no detrmental effect on the qualty of the ol. Qualty of the ols, as ndcated by ther physcal and chemcal characterstcs, s de pendent upon the yeld of ol obtaned. It s also determned by the quantty of aqueous phase that comes n contact wth the ol dur ng processng, snce the aldehyde content of the ol s affected by ths factor. It was also shown that as the yeld of ol per ton of frut ncreased, the aldehyde content of the ol n creased. Whle ths study s on the bass of only one year's work, t defntely shows that certan of the lemon selectons gve ols whch meet the specfcatons of the Unted States Pharma copoea and other hgh-qualty requrements. If the proper lemon s selected and the ol manufactured carefully, Florda can produce a lemon ol superor to any now produced n the Unted States. An nvestgaton was made to determne the boflavonod content of 42 lemon selec tons. Chromatographc and ultravolet evalu aton of the boflavonods showed them to be predomnantly hesperdn. If hesperdn s the only boflavonod of commercal mportance, lemons would not appear to have a compet tve advantage over oranges snce yelds are comparable. LITERATURE CITED. Davs, W. B. Determnaton of flavanones n ctrus fruts. Anal. Chem. 9: Hendrckson, R. and J. W. Kesterson. Hesperdn the prncpal glucosde of oranges. Florda Agr. Exp. Sta. Bu. 545: Hood, S. C. Relatve ol yeld of Florda oranges. Ind. Eng. Chem. 8: Kesterson, J. W. and R. Hendrckson. Essental ols from Florda ctrus. Florda Agr. Exp. Sta. Bu. 52: Merck Index of Chemcals and Drugs. 6th Ed. Merck & Co., Inc., Rahway. 67 pp IV. FLORIDA LEMONS FOR FRESH FRUIT USE W. Grerson Florda Ctrus Experment Staton Lake Alfred The role of lemons as a fresh frut crop n Florda s not lkely to assume major propor tons, especally as the new plantngs tend to be prmarly for cannery use (2). Neverthe less, the study reported n ths seres of papers would be ncomplete wthout some nvestga ton of the possbltes of these selectons when handled as fresh frut. Florda lemons are usually apt to be con demned out of hand as beng too large and coarse for the fresh frut market. Ths vew seems to have become generally accepted wth out crtcal evaluaton. Attenton s therefore drawn to the followng descrpton of the Calforna lemon ndustry pror to 870. It s taken from the well-known text "The Ctrus Industry" (0). "... lemons were grown to be sure, but Florda Agrcultural Experment Staton Journal Seres, No. 89. n the markets of San Francsco the fruts were consdered to be btter and much n feror to lemons mported from Italy... The Calforna fruts were allowed to rpen on the trees and were consequently large and coarse, whereas the Italan fruts were pcked as early as possble and by reason of the long shpment tme reached the markets thoroughly cured... the great development of the ndus try n Calforna came only after the n troducton and selecton of good varetes and the dscovery of proper methods of pckng and curng." It would not be true to say that the poss blty of Florda lemons respondng to proper curng procedures has always been gnored. In a 923 address to ths Socety, F. G. Samp son detaled the spot-pckng, curng and handlng methods that had enabled hm to shp as many as 47,000 boxes of lemons n a sngle year and to receve prces up to $8.75 per box on the Boston Market (8). More re cently (943) Wnston and Meckstroth dem-