Journal of Sc ientifi c & Industri al Research Vo1.61. October 2002. pp 823-827

Canning of Peach-halves in Fruit Juice

KD Sharma*, Mani sha Kaushal and 88 Lal Kaushal Depart ment of Posth arvest Technology. Uni versity of Horticulture & Forestry, So lan. 173 230

Received: 27 A ugust 2001 : rev ised: 23 July 2002: accepted 02 A ugust 2002

Lye pee led peach hal ves of July Elber/a canned in A2Y2 size tin cans in a covering mediu m of 40"13 in di fferent proporti ons ( I 0-40 per cent, peach pulp and enzymat ica lly extracted pcach j uicc with or wi thout ascorbi c ac id at 500 ppm) were eval uated for storability. nutritional value and sensory attri butes. Cut-out ana lys is of ca nned fru i ts after 6 mo revealed th at all the trcatm c:nts met FPO specifications for drained weight and showed improvement over the conventional canned peaches. A s ex pected the vitam in C fort ified treatments retained higher amounts of· ascorbic acid. Addition of pul p or j ui ce in covering media prevented the non-enzymati c browning to a greater ex tent. Rased on the sensory eva luati on the addition of juicc or pulp in co vering syru p signifi cantl y improved the sugar/acid blend of the canned halves. Treatment contain ing 40 per cent peach pulp was rated as the best treatment followed by 30 per cent peach pulp in a coveri ng medium of 40 "13 on the basis of ph ysico-chemical. sensory and microbiological evaluati on. The additional advantage of canning of fruit s in natural fruit j uice or pulp occurred due to the use of covering sy rup in the preparati on of the ready-to-serve-beverage (RTS) o f 15 "13 prepared from the leftover cove ring mediu m containing 40 per cent peach pulp and was rated best on the basis of sensory qualit y. Overall it can be concluded th at sucrose syru p being used in cann ing of peach halves at present can success full y be replaced w ith the covering medi um containing 30-40 per cent of peach pul p. Add ition of pul p or j uice not onl y improve the qualit y o f cann ed product but. enhance its nut rition along w ith the c:conomic utili zati on of the left over covering medi a in the form of RTS beverage.

Introduction Peach (Prunus persica Barsch.) is one of the impor­

tant stone fruit s mostly grown in temperate regions of the world . Indi a contributes 57 thousand tonne to the world peach producti on1 of 7,979 thousand tonne. In India, its culti vati on is confined to low- and mid-hill ar­eas of Himalayan region with the exception of some low chilling culti vars which are being grown under sub-tropi ­cal conditi ons of northern pl ains. Himachal Pradesh pro­duces2 356 t peaches/y from 5,71 2 ha. The fruit con­tains.1 7-8 per cent sugars, 0.6- 1.2 per cent proteins, 1-27 mg/ 100 g vitamin C along with significant amounts of minerals and vitamins. Due to short shelf-life of and fur­ther mving to the peri shable nature of peaches, non-avail ­ability of storage faciliti es in growing areas and lack or cold-chain transportation, the growers get un sati sfactory returns on the produce. Therefore, to make fruit s avail ­able throughout the year to consumers and for better re­turns to growers, preservati on of fruit hal ves could be an attrac ti ve alternati ve. Some workers have suggested replacement of the sugar syrup with corn syrup in can ­ning of fruits4

. Apple juice has been used for canning of stone-free peaches' . Additi on of 15 per cent mango pulp and 20-30 per cent of the appl e juice concentrate of

· Corresponding aut hor

35 "8 in covering syrup has success full y been used in the canning of mango and apple rings, respec ti vely<>- 7.

Hence the present in ves tigati on was carried out to ex­plore the poss ibility of using peach pul p or juice, at dif­ferent levels. in the canning of peach halves to obtain a product having good nutriti on with better retention of quality during storage.

Materials and Methods

Prepa ration of Fruit , Pulp and Juice

Firm ripe fruits of peach culti var July Elberta were obtained from Raj garh area of Himachal Pradesh, known for quality peach·production . The sound peach fruits were manually sorted. graded, washed, and di vided into two lots. One lot was lye-peeled by clipping fruits in 1.0 per cent boiling caustic soda for 50-60 s. The lye-peeled frui ts were hal ved by remov ing the pit. The other lot was pulped with 10 per cent water, cooked fo r 10- 15 min , passed through the pulper and pas teuri zed fo r 20 min after pou r­ing and sealing into the sterili zed glass bottles . For ex ­trac ti on ofjuice, the pulp was treated with pectinase (0.5 per cent) and incubated at 40 oc fo r 4 h. Later, the en­zy me treated pulp was passed through muslin cloth, and the extracted juice was heated to 95 "C to inacti va te the added enzy me and then stored in sterili zed glass bottl es after pas teuri zing for 20 min .

••'.•II:

824 J SCT TND RES VOL 61 OCTOBER 2002

Packing and ProcessingLye peeled peach halves were packed in A2112 cans

with a covering medium of 40 °8 strength containing10-40 per cent peach pulp or peach juice, as preparedabove, with or without 500 ppm ascorbic acid. The con-ventionally canned samples with covering syrup of 40"8 strength (prepared with sucrose and having 0.3 percent citric acid) constituted the control. The processingof packed tin cans was done as per the standard method"and the processed cans were stored at ambient tempera-ture (12-28 °C) for 6 months. The experiment was repli-cated thrice.

AnalysisThe physico-chemical analysis of the fresh and

canned fruits was carried out according to the proce-dures described by Ranganna". The overall acceptabil-ity evaluation offruit halves as well as the covering mediawas carried out by a panel of7 semi-trained judges on a9-point Hedonic scale!". The data were statistically ana-lyzed and means compared at 5 per cent level of signifi-cance".

Results and Discussion

Characteristics of Fruit

Fresh fruits were analyzed for their physico-chemi-cal characteristics before canning and the results are sum-marized in Table 1. The average truit length and widthof the peach cultivar July Elberta fruits were 5.82 and5.95 em, respectively. The weight and volume ofthe fruitswere 82.60 g and 75.80 em", respectively, with firmnessof 5.23 kg/crrr'. The fruits were greenish yellow in colour.The status of various chemical parameters in fruits wereas follows: moisture 88.10 per cent, total soluble solids(TSS) 11.43 °8, titratable acidity 0.76 per cent as malicacid with a TSS/acid ratio of 14.83. Reducing and totalsugars, ascorbic acid, and total carotenoids were 1.80and 9.30 per cent, 16.40 mg/l 00 g and 690 /lg/lOO g,respectively. It was apparent from the physico-chemicalcharacteristics of the peach fruits that the fruits weresuitable for canning.

Characteristics of Canned Peach-halvesThe cut-out analysis results of canned peach-halves,

stored at ambient temperature for a period of six months,are presented in Table 2. The results presented show thatthere was an increase in drained weight in all the treat-ments with the lowest and highest drained in treatments

Parameter

Table I-Physico-chemical characteristics of fresh peach fruit

Mean' Standard deviation

Length. emWidth,cm

Weight, g

Volume. crrr'Specific gravity

Fruit colourPulp to stone ratioFirrnness, kg/ern?

Moisture, per centTotal soluble solids, °BTitratable acidity. percent as malic acid

Sugars. per cent

ReducingTotal

Ascorbic acid, mg/l OOg

Total carotenoids, flgllOOg

TSSllacid ratio

*Average value of 10 fruits

5.82 0.02

5.95 0.03

82.60 4.967S.HO 3.40

1.09 0.02Greenish yellow

20.40 o.so5.23 0.3088.10 0.8011.43 0.17

0.76 0.02

1.80

9.3016.40

690.0

14.83

0.0 I0.050.52

0.12

0.10

with 20 per cent peach pulp and 20 per cent peach juicein a covering syrup of 40 °8 containing 500 ppm ascor-bic acid, with drained weight of 54.65 and 58.99 percent, respectively. Even the lowest drained weights dueto the treatments given to canned peach-halves werehigher than that of controls which was 54.65 per cent. Adrained weight of 55.0,56.0 and 57.0 per cent in peachhalves canned in plain sugar syrup, reconstituted in applejuice concentrate medium and straight apple juice me-dium, respectively, has been reported earlier by Vyas andJoshi'. All the treatments reported in this paper meet theFPO specification" for the minimum drained weight. Anincrease in TSS due to sugar diffusion during the equi-librium process on storage was noticed in all the treat-ments.

The titratable acidity decreased in all the treatments,however, it was found to be comparatively higher inpeach-halves of similar treatments where the juice wasincorporated in the covering syrup instead of pulp. hwas simply because the initial acidity of extracted peachjuice was higher than that of the pulp. In general, therewas a reduction in acidity of peach-halves as the acidsmight have been used in the hydrolysis of sucrose to

SHARMA e1 a/.: CANN ING OF PEAC H-HALVES

Table 2- Cut out exami nation of canned peach halves after 6 months of storage

Parameter Covering Ascorbic Concent ration of pu lp or juice, per cent Mean

med ia ac id. ppm 10 20 30 40

Drained weight, per cent

Pulp 0 56.63'"' 57.60' " 57.3 1 hll 57.49"'" 57.26

500 57.86' 11 54.96''A 57 . II ,·A ll 56.8 1bA 56.68

Jui ce 0 56.72"A 58.25'( 56.87"' 57.35bll 57.30

500 57.75' 11 58.99' 0 57.78"' 58.04h(' 58.14

Mean 57.24 57.45 57.27 57.42

Total soluble solids (TSS), per cent

Pulp 0 22. 13''11 24.20"11 22.27"11 24.33b(' 23.23

500 22.60UC 2 1. 33"" 19.47'"' 22.20'A 21.40

Jui ce 0 24.27dD 2 1.33'"' 23.93'(' 23.20"11 23.18

500 2 1.J3bA 2 1.40hA 19.53 'A 22.33'A 21.15

Mean 22.58 22.06 21.30 23.02

Titratable acidity, per cent

Pulp 0 0.14"A 0.23 bA 0.32'A 0.36dA 0.24

500 0.22,(" 0.26"11 0.33'A 0.37dllA 0.29

Juice 0 0.17"0 0 .26bll o.35'·n 0.38dUC 0.26

500 0.22"(' 0.30bC 0 .36'u 0.39d(' 0.34

Mean 0.21 0.26 0.34 0.32

Ascorbic acid, mg!IOOg

Pulp 0 4.60'A 4.50'" 6.42"" 7.39' A 5.73

500 10.71'' 13.83'" 15.65'c 15 .7 1' (' 13.97

Jui ce 0 5. 14"" 5.35"u 7.15"1l 8.44' 11 6.52

500 11.51"" 14.53"" 16.39") 19.67dD 15.52

Mean 7.99 9.55 11.40 12.80 lo.43

Non-enzymatic browning, optical density at 440 nm

Pulp 0 0.150"(' 0. 1 3 1 1~ · 0.137 '" 0. 106£ 0.131

500 0.08l 'A 0.050'A 0.066"" 0.066bA 0.065

Jui ce () 0. 176"!) 0 .1 82' !) 0. 180") 0 .1 66' 0 0.176

500 0.089'0 0.064"11 0.076"11 0.093"11 0.080

Mean 0.124 0.107 0.115 0.108

"Drained weight. total soluble so lids, titratable acidity, ascorbic acid and non-enzymatic brown ing for control samp les after 6 mo of storage was 54.65. 25.33, and 0.23 per cent, and 3.9 1 mg/1 OOg and 0. 184, respectively " Initial total so luble solids of covering media 40 per cent. Control treatment (conventional canning media) contained 40 "8 sucrose syrup hav ing 0.3 per cent c itric acid Values bearing the same small letters in a row and capital letters in a co lumn within each parameter are not signifi cant ly d ifferent (p > 0.05)

825

826 J SCI INO RES VOL 61 OCTOBER 2002

simple sugars and also due to the leaching into the cov-ering medium on storage. The highest acidity of 0.39per cent was recorded in the treatment containing 40 percent peach juice in a covering media of 40 °B having500 ppm ascorbic acid and the lowest value of 0.14 percent in treatment containing 10 per cent peach pulp in acovering media of 40 °8. The acidity was comparativelyhigher in control samples, conventionally canned peach-halves, at 0.23 per cent in comparison to the treatmentscontaining 10 per cent peach pulp or peach juice with orwithout added ascorbic acid mainly due to the fact that0.30 per cent of citric acid was added in the sucrose syrupof peach-halves canned under the conventional method.

The data on the retention of ascorbic acid in cannedpeach-halves revealed that although, there was a reduc-tion in the vitamin C, the retention of ascorbic acid washigher in vitamin C fortified treatments. The deliberateaddition of ascorbic acid not only enhanced the nutri-tive value of the canned product but also reduced non-enzymatic browning to a greater extent. The highest andlowest levels of ascorbic acid in ascorbic acid fortifiedtreatments were 19.67 and 10.71 mg/lOO g in treatmentcontaining 40 per cent peach juice in a covering mediaof 40 °8 having 500 ppm of ascorbic acid and treatmentcontaining 10 per cent peach pulp in a covering mediaof 40 °B having 500 ppm of ascorbic acid, respectively.On the other hand, in unfortified treatments the highestand the lowest levels of retained ascorbic acid were 8.44and 4.50 mg/JOOg in treatment containing 40 per centpeach juice in a covering media of 40 °B and treatmentcontaining 20 per cent peach pulp in covering media of40 "8, respectively. The control samples contained thelowest level of ascorbic acid at 3.91 mg/IOOg. Garg eta/.13 have observed that the ascorbic acid in cannedpeaches declined by 80.0-81.0 and 78.0-82.0 per cent inCrawford Early and Golden Bush cultivars of peaches,respectively.

Non-enzymatic browning was recorded as the high-est in control samples, canned conventionally, record-ing an optical density of 0.184 as compared to the samplespacked in a medium containing fruit juice or pulp, and itwas much lower in the vitamin C fortified samples. Itmay be due to the antioxidant effect of the vitamin C.The highest and lowest levels of optical density at 440nm were 0.182 and 0.106, for the unfortified samplescontaining 20 per cent peach juice and 40 per cent peachpulp in a covering media of 40 °B, respectively. Whereas,in ascorbic acid fortified samples the highest and lowest

I••II

levels of the optical density were 0.093 and 0.050 corre-sponding to treatments containing 40 and 20 per centpeach pulp in a covering media of 40°8 with 500 ppmascorbic acid, respecti vely.

Sensory quality evaluation of peach halves carriedout by a panel of 7 semi-trained judges revealed that allthe treatments showed an improvement over controlsamples. On the basis of different sensory quality pa-rameters, viz; colour, flavour, taste and texture, the treat-ment containing 40 per cent peach pulp was rated as bestover six months of storage period, followed by samplescontaining 30 per cent peach pulp, \0 per cent peachpulp with 500 ppm ascorbic acid, 20 per cent peach pulp,20 per cent juice with 500 ppm ascorbic acid, 20 percent peach juice, and 40 per cent juice with 500 ppmascorbic acid, all in a covering media of 40 "8, and re-corded overall Hedonic rating of 6.25,5.79,5.79,5.62,5.46,5.25 and 5.11, respectively, on the nine-point He-donic scale (Table 3). Hulmel.l has reported that addi-tion of acid leads to a firmer and crispy texture of peaches.Conventionally canned peach halves have been reportedto be acceptable up to 200 d by Kinge".

Ready-to-serve (RTS) beverage prepared from thecovering media after draining the peach halves and re-constituting the leftover covering media to 15 "8 bever-age with water was also evaluated by the panel of sevensemi-trained judges and the results are given in Table 3.Overall acceptability score based on the observation fordifferent sensory attributes, viz: colour, flavour, taste andconsistency/body showed that the conventionally cannedsample (sucrose syrup of 40 "8 with 0.3 per cent citricacid) resulted in unacceptable RTS beverage with a meanrating of 2.00. The highest rating of 6.38 was recordedfor the RTS beverage prepared from samples containing30 per cent peach pulp, followed by those containing 30per cent peach pulp with 500 ppm of ascorbic acid, 20per cent peach pulp and 40 per cent peach pulp with 500ppm ascorbic acid, all in a covering media of 40 "8, withratings of 6.29, 6.26 and 6.18, respectively. Khurdiyaand Roy? have suggested earlier that the covering mediacontaining mango pulp left after consuming cannedmango slices can be utilized as ready-to-serve beverage.

From the present study, it may be concluded that thesucrose syrup being used in canning of peach-halves atpresent can successfully be replaced with the coveringmedium containing 30-40 per cent peach pulp. Additionof pulp or juice not only improved the quality of canned

SHARMA er a/.: CANNING OF PEACH-HALVES 827

Table 3- 0vera l l acceptability" score of canned peach halves and ready-to-serve beverage after six months of storage

Product Covering media· Ascorbi c Concen tration of pu lp or juice, per cent Mean

acid, ppm 10 20 30 40

Canned peach halves

Pulp 0 5.1 8" 11 5.62 1~ · 5.79/:C 6.25'"<" 5.71

500 5.79',. 5.46"-'IIC 4.96·'A 5.2 J obAB 5.35

Juice 0 4.7)"A 5.2)hAII 4.89'"' 5.50"" 5.10

500 5.39"" 5.00"A 5.J4"B S. IJ "A 5.1 6

Mean 5.28 5.33 5.19 5.52

Ready-to-ser ve beverage

Pulp 0 5.46'""' 6.11 "" 6.38'..:· 6.26bU 6.05

500 5.74"(" 6. 18"" 6.29bBC 6. 14"" 6.09

Juice 0 5.29'"' 6.00"Il 5.96bA 6.07"1l 5.83

500 5.61 bllC ).J 8"A 6. II , ·AI) 5.5Q"bA 5.60

Mean 5.52 5.87 6.1 8 5.99

•on nine point Hedonic scale 'Overall acceptability score for control (conventionall y) canned peach halves and ready-to-serve beverage is 3.71 and 2.00. respectively

" Initial total soluble so lids of covering media 40 °B

Values bearing small common letters in a row and capital common letters in a co lumn with in each parameter are not significantly different (p > 0.05)

product but also enhanced its nutntton along with the economic uti lization of the leftover covering media in the form of ready-to-serve beverage.

References

2

4

5

6

FAO. Producrion vear book (Food and Agriculture Organ iza­tion. Rome) 1998.

Anonymous. Alll/ua/ report (D irectorate of Horti culture Himachal Pradesh. Shimla) 1999.

Salunkhae D K & Kaclam S S. Handbook offruir scie11ce and rech11ologv. pmducrion a/1{1 co1nposirion (Marcel Dekker Inc, New York) 1995.

Pangborn R M. Leenard S, Luh B S & SimmonS. Free stone peaches-effect of citric acid, sucrose and sour syrup on con­sumer acceptability. Food Tecluwl. 13 ( 1959) 444-447.

Vyas K K & Joshi V K, Canning of fruits in natural fruit juices I. Canning of peaches in apple juice. J Food Sci Techno/, 19( 1982) 39-40.

Khurdi ya D S & Roy S K. Stud ies on cann ing of mango slices in covering sy rup containing mango pulp. 111dia11 Food Pel.:~; 40 ( 1986) 50-54.

7

8

9

10

II

12

14

15

Sharma K D, Sethi V & M aini S B, Studies on incorporation of concentrate in covering syrup for processing of apple rings in tlex ible pouches, J Food Sci Techno/, 35( 1998) 37 1-374.

La l G. Siddappa G S & Tandon G L. Preservarion of fruirs a11d l'egewb/es (ICAR, New Delhi ) 1959.

Ranganna S, Handbook of analysis and qualiry COI/lrol for .fi"uir and vegerab/e producrs (Tata McGraw Hil l Publishing Company Ltd. New Delhi) 1986.

Amerine M A. Pangborn R M & Roess ler E B. Principles ol sensory eva/uarion oflood (Academic Press. New York ) 1965.

Cochran W G & Cox G M , Experime11ra/ desig11s (Asia Pub­l ishing House. Bombay) 1963.

FPO, Fruit products order (Department of Foods, Ministry of Agri culture, Government of India. ew Delhi ) 1955.

Garg R C. Ram H B. Srivastava R K & Singh S K. Physico­chemica l studies on optimum stage of malllrity for canning of peaches in Uttar Pradesh. Prog !-/orr. 6 ( 1975) 57-66.

Hulme A C, The bioche111isrrv offruir.~ and their products (Academic Press. New York ) 197 1.

Kinge R. Swndardi:arion of 1/Wiurirv indices o{peach ill re­larioll ro conning and table p111pose. M .Sc Thes is (Uni ve rsity

of Hort iculture and Forestry. Solan. Himachal Pradesh) 1992.