Impact of Drying Methods on Physicochemical and Sensory Properties of Apricot Pestil

Indian Journal of Traditional Knowledge Vol. 13 (1), January 2014, pp. 47-55

Impact of drying methods on physicochemical and sensory properties of apricot pestil

Senem Suna, Canan Ece Tamer*, Bige İncedayı, Gülşah Özcan Sinir & Ömer Utku Çopur Department of Food Engineering, Faculty of Agriculture, Uludag University, 16059 Gorukle, Bursa, Turkey E-mail: [email protected]

Received 28.06.13, revised 19.08.13

Fruit leathers, or traditionally named as pestil are intermediate moisture pectic gels, eaten as snack, manufactured by dehydration of fruit pulp into leathery sheets. The aim of the study was to evaluate physicochemical and sensory properties of apricot pestil dried with different methods. One group was sun dried, other group was dried in vacuum oven at 55°C and the last one was dried in microwave oven (90 W). Analysis of moisture, water soluble dry matter, pH, titratable acidity, total and reducing sugar, hydroxymethylfurfural, total phenolic compounds, antioxidant activity, minerals (K, Ca, Mg, Zn), color (L*, a*, b*) and sensory analysis were carried out. The moisture contents of apricot pestil samples were between 13.12±1.35 - 14.39±0.41 gm/100 gm. The HMF content of samples was affected by drying method. The HMF contents of microwave oven dried, vacuum oven dried and sundried pestil samples were 13.62±0.78, 19.39±0.26 and 45.64±1.29 mg/kg, respectively. Total phenolic compounds in samples were determined as between 110.03±0.72 - 121.24±6.19 mg GAE/100 gm. Retention of antioxidant activity of the sundried, microwave oven dried and vacuum oven dried samples was 59.80%, 39.23% and 19.15%, respectively. The mineral contents of pestil samples were higher because of increasing dry matter content. When comparing drying times, the shortest was observed in microwave oven drying followed by sun drying and vacuum oven drying. Drying methods considerably influenced the color changes of pestil samples. Chromatic parameters a*, b*, ∆Eab* and C*ab were found higher in microwave oven dried samples. Sensory evaluation analysis showed that all of the samples were acceptable by the panelists. The results of the analysis were important for selecting the quality criterion and for characterizing of this traditional product.

Keywords: Apricot pestil, Antioxidant activity, Total phenolics, Microwave oven drying, Sundrying

IPC Int. Cl.8: A61K 36/00, C09K 15/00, G01N, F26B, A23B 7/00, A23N 12/00

Dried fruits and vegetables have been regarded as Pestil is one of the most important traditional foods alternative fat free snacks and received more attention produced and consumed in different regions of from the food industry during the past decade1. Turkey. There are grape pestil, apricot pestil, plum Fruit leathers are dehydrated fruit based products that pestil and mulberry pestil, among others4,5. Fruit are eaten as candy or snacks, and presented as flexible combinations make a variety of flavors possible. stripes or sheets. The origin of fruit leathers may go However, acceptable leathers cannot be prepared back to the Persian Empire. They are known as Pestil from juicy fruits until suitable additives such as in Turkey and Fruit leather in the United States. They maltodextrin, pectin, soluble starch, carboxy methyl 6 receive this name because of the final product aspect cellulose, etc. are added . The processing steps of (it is shiny and has the texture of leather)2. The drying pestil depend on the fruit used and, for apricots, of fruit to prepare leathers offers a convenient method consist of sorting, washing, pitting, pre-heating, of marketing fruits that are abundant for fresh fruit pressing, starch addition, evaporation, spreading, 5,7,8 market3. Due to their attractive appearance, and drying, cutting and packaging . Moisture is because they do not normally require cold storage to removed from a large flat-tray of wet puree until the 9 avoid microbial growth, fruit leathers constitute a desired cohesive ‘leathery’ composition is obtained . practical way to increase fruit solids consumption, When dried, the product is pulled from the surface, especially for children and young people2. rolled and consumed as snack. Control of the drying temperature is very important, as very high values —————— often cause surface hardening, hindering the outflow *Corresponding author of water. Besides, controlling the fruit puree load is 48 INDIAN J TRADITIONAL KNOWLEDGE, VOL. 13, No. 1, JANUARY 2014

also important, as if the puree layer is excessively United States, dehydrated fruit leathers have been thin, the resulting product may be brittle and difficult utilized, by astronauts during space explorations, by to remove from the surface. In contrast, a too thick explorers, hikers, backpackers and others who must 20,23 puree layer results in a very low drying rate10. carry their food supplies along with them . Drying of fruit leather is a process which involves Undoubtedly, fruit leathers have a steady and growing 24 simultaneous heat and mass transfer11. Various market that exists in United States and Canada . methods of drying and drying conditions affecting Confectionary like sweets and candies made from a quality of fruit leathers have been previously studied high amount of sugar, has very little nutritional value 10,13,15,19,21. Sun drying allows the production of a and could cause tooth decay among children. Fruit pestil with a live color and translucent appearance. leathers could be an alternative confectionary not only to children but to adults as well25. However, the drying time is long and dependent on The apricot (Prunus armeniaca L.) fruit is weather conditions, while the product is exposed to considered as one of the most delicious temperate environmental contamination. Microwave oven fruits and consumed because of its delicate flavor and drying usually takes a shorter time to dry pestil high nutritional quality26. The greatest percentage samples compared with other methods of drying. Hot of the world’s apricot production comes from the air drying is a conventional drying method, which countries around the Mediterranean Sea, that is decreases drying time. However, conventional drying Turkey, Spain, Italy, France and Greece. Apricots with high air temperature and long drying time may could be consumed as whole fresh fruits, fruit juice, cause serious damage to quality attributes of the dried fruits, fruit puree, jam, marmalade, pestil or product such as flavor, color, nutrients, and reduction as vinegar26,27. It is a rich source of carbohydrates and in bulk density and rehydration capacity of the dried minerals besides having attractive color and typical product12. For this reason, different dehydration flavor28. Sugars like glucose, fructose, sucrose, processing schemes have been proposed for the sorbitol, and malic and citric acid are the principal production of fruit leathers including single type constituents. Apricot is also a good source of minerals dehydration or combined methods of drying13. such as potassium and iron. The apricot fruit is Natural fruit pulp based fruit leathers are nutritious an important source of provitamin A carotenoids since and organoleptically acceptable since substantial 250 gm of fresh or 30 gm of dried fruit provides quantities of dietary fiber, minerals and vitamins are 100% of the RDA of carotenoids. The major 14 carotenoid compound found in apricots is β-carotene, the constituents of final product . Pestil is pleasant to constituting 60-70% of the total carotenoid level. chew and quite tasty. As, it is low in moisture, stored The major phenolic compounds in apricot are for a long term period and economical to ship when 9,16,17 chlorogenic and neochlorogenic acids, (+)-catechin, comparing with fresh fruit . Pestil production is (-)-epicatechin and rutin (or quercetin-3-rutinoside)29. used to increase shelf life and protect nutrients for The aim of this work was to describe the effect of longer periods especially during winter. Pestil is a drying methods such as sundrying, vacuum oven good source of carbohydrate, energy, minerals such drying and microwave oven drying on as, Fe, F, Ca, K and vitamins especially thiamine and 8 physicochemical properties and retention of some vitamin B6. Çağındı and Ötleş also mentioned that nutrients, antioxidant capacity and organoleptic apricot pestil is rich in potassium, calcium, sodium quality of apricot leathers. The technical knowledge and zinc. According to the results of their research, about drying process is based on many literatures. apricot pestil (100 gm) would be sufficient to provide But the researches about different kinds of pestils and approximately 70% of the potassium, 20% of the drying methods are limited. So, this research sodium and 30% of the iron needed for the is focused on apricot leather production and Recommended Daily Allowance (RDA). the effects of different methods on numerous It is worth to note that fruit leathers, which is a parameters as practically. value added product, have a steady and growing market and are well established products, particularly Materials and Methods 3 in the American market . It is becoming a popular alternative to fresh fruits and the demand for fruit Materials leather is increasing constantly in the international Apricots were harvested in an orchard in Malatya market18. Fruit leather is easy to eat, convenient to province, Turkey, in August 2011 and stored ±4 ºC. pack, and makes an ideal snack almost anywhere. In Prior to pestil preparation, apricots were taken out of SUNA et al.: IMPACT OF DRYING METHODS ON PHYSICOCHEMICAL AND SENSORY PROPERTIES OF APRICOT PESTIL49

storage and processed. Starch (4 %) was used for the identified by measuring the absorbance variation of aimed viscosity of the mixture and the sensorial the samples by barbituric acid and p-toluidine, using a improvement of this traditional product13. Distilled spectrophotometer 30,34. The procedure carried out to water was used for all experiments. determine antioxidant activity in apricot and apricot pestils was based on inhibition of the free radical 2,2- Preparation of pestil diphenyl-1-picrilhydrazil (DPPH) in methanolic Fruits were washed, cut and pitted then processed extracts of the samples. DPPH radical has an intense using a domestic blender (Beko, Turkey), until violet color but turns colorless as unpaired electrons obtaining a homogenous pulp. Initial total soluble are sequestered by antioxidants. In this method, solid (ºBrix) of pulp was 20 gm/100 gm. 3/4 part of extracted samples, which were made to react with the pulp was boiled in an open kettle for 20 min at radical solution and rest for 30 min at room constant stirring to obtain paste with 45 °Brix. Then, temperature, were measured for absorbance at 517 freshly prepared wheat starch and pulp mixture nm, and the inhibition percentage of DPPH free (starch dissolved in 1/4 part of pulp left) was added to radical was calculated32. The extracts for antioxidant the boiling paste. This was done to prevent formation activity were tested at concentration of 8 mg/ml on of lumps and uniformly disperse the starch. It was dry basis. Antioxidant activity values were analyzed boiled for 5 min more. Cooked apricot paste–starch on dry basis for comparing the raw material and pestil mixture (approximately 100 gm) was evenly spread samples with different dry matter contents. The on a 20 cm diameter cloth. The samples were dried method employed for the total phenolics was based on from one side (top surface). The drying methods were Folin-Ciocalteau’s phenol reagent, followed by sun drying under direct sunlight (345 min), vacuum spectrophotometric determinations carried out at 452 oven (Nüve EV 018, Turkey) drying (55°C, 720 mm nm using a Shimadzu UV 1208 equipment, and the Hg, 450 min) and microwave oven (unmodified results were calculated as gallic acid equivalents33. commercial Bosch Hmt72g420, Germany, 2450 For determination of color values, Hunter colorimetric MHz) drying (90 W, 55 min). The weather system was applied by Miniscan EZ4500L model temperature was around 30-31°C, the percent average HunterLab colorimeter. The measurements were relative humidity was 58 and UV intensity was high displayed in L*: lightness, a*: redness, b*: (7-8 UV index). The drying experiments were yellowness. The surface color of pestils was measured conducted in duplicate. The appearance of pestil was on different parts and expressed as the mean of three yellowish orange with a smooth surface. After drying, replicate readings. Total color difference (∆Eab*), pestil samples were pulled from the surface and chroma (C*ab) and hue angle (h°) values were packaged with low density polyethylene film and calculated from L*, a*, b* values31. For analysis of stored at room temperature until analyzed. the mineral content NMKL (2007)36 method was employed and Agilent 7500 CX (Agilent Physicochemical analysis Technologies, Santa Clara, CA, USA) model ICP-MS Moisture content, water soluble dry matter, pH, was used. According to this method, 0.5 gm titratable acidity, total and reducing sugar, total homogenized sample, 4 mL HNO (65%) and 1 ml phenolic compounds, antioxidant activity, content of 3 H2O2 (35%) were incinerated in microwave digestion minerals (K, Ca, Mg, Zn), surface color (L*, a*, b*) system (Berghof mws3). The digested sample was and sensory analysis were conducted. Moisture of transferred to a 50 mL volumetric flask and diluted pestil samples was determined by oven drying 30 with distilled water. Triplicate measurements were method . Water soluble dry matter of apricot pulp performed for all physicochemical properties in each was expressed as gm /100 gm by using an Abbe batch of apricot pestil samples37. refractometer. Titratable acidity was determined by diluting 5 gm of the pulp with 50 ml of distilled water Sensory analysis and titrating to pH 8.1 with 0.1 N NaOH and Sensory attributes of products as color, appearance, expressed as citric acid content. The pH of apricot taste and chewiness were evaluated by five trained pulp was measured by using a Sartorius Basic PB-11 panelists selected among staff and graduate students Model Laboratory pH meter. Total and reducing of the Food Engineering Department (Uludag sugars were determined by the Luff-Schoorl University). A 9-point structured hedonic scale was method31. Hydroxymethylfurfural (HMF) was used to evaluate the samples. The results were rated 50 INDIAN J TRADITIONAL KNOWLEDGE, VOL. 13, No. 1, JANUARY 2014

on points as 9: like extremely, 8: like very much, variance (ANOVA) using the JMP software package 7: like moderately, 6: like slightly, 5: neither like nor version 5.0 (SAS Institute Inc. NC, 27513). dislike, 4: dislike slightly, 3: dislike moderately, The significance of the treatments was determined at 2: dislike very much, 1: dislike extremely (Fig. 1). the 0.05 probability level by using LSD test. The samples were coded with three digits random numbers, not more than three samples were served in Results and discussion a randomized order. Prior to the test, panelists were Three different drying methods were compared by briefed about the questionnaire and instructed to plotting percentage of remaining weight vs. drying visually evaluate product acceptability for color and time38 (Fig. 2). The time of drying in manufacturing appearance. Afterwards, they were instructed to of fruit leathers vary, depending on the type of fruit masticate a piece of the test sample and before and the dryer used. The high temperature of the providing acceptability ratings for chewiness and drying process is an important cause for loss of taste. Unsalted crackers and water were provided in quality. For this reason, lowering the process between samples. temperature has great potential for improving the

quality of dried products. Vacuum drying is an Statistical analysis 39 The experiment was conducted in a completely important process for heat sensitive materials . randomized design with two replications. The results Percentage of remaining weight was found as 51.5, were statistically evaluated by one-way analysis of 53.3, 52.2 for sun dried, vacuum oven dried and microwave oven dried samples respectively at the end of their drying period. According to these data, microwave oven drying (55 min) was the fastest method followed by sun drying (345 min) and vacuum oven drying (450 min). Use of microwave energy in drying offers reduced drying times and complements conventional drying in later stages by specifically targeting the internal residual moisture39. Maskan et al.13 mentioned that depending on sample thickness and air temperature, the drying time ranged between 50–140 min to achieve the commercial moisture content of grape pestil (0.12 kg H2O/kg dry solids) in air drying. Whereas, sun drying took 180–1500 min in this study. Analytical results pertaining to proximate composition of the apricot fruit used for pestil production are presented in Table 1. Mean values of total dry matter, pH and acidity were similar to those reported by Hacıseferoğulları et al.40 who determined postharvest chemical and physical–mechanical properties of some apricot varieties cultivated in Turkey. They determined dry matter as between 16.73–22.63%, pH as 4.16-5.23 and acidity (malic acid) as 0.17– 0.79%. Drogoudi et al.29 evaluated physical and chemical properties of apricot cultivars of Greek and American origin and their hybrids. They determined total sugars as between 43.1 - 62.2 % (dry weight), total phenol content between 0.303 and 7.422 mg gallic acid equivalent gm-1 fresh weight. The amount of total phenolics in fresh apricot sample was comparable with results reported by Ruiz et al.41

(0.202-1.202 mg gm-1 fresh weight). K, Ca, and Mg Fig. 1—Sensory evaluation of apricot pestil samples based on 29 hedonic scale are considered as major minerals of the apricot fruit . SUNA et al.: IMPACT OF DRYING METHODS ON PHYSICOCHEMICAL AND SENSORY PROPERTIES OF APRICOT PESTIL51

Hacıseferoğulları et al.40 measured higher amounts of K (20791-33364 ppm), Ca (843.28-1896.53 ppm) and Mg (402.82-765.62 ppm) in apricot samples. According to many studies, composition of the fruits was affected by climate, variety, geographical origin, harvest year and the methods of cultivation42. Color values coincided with results reported by Ihns et al.43 They determined the average L*, a* and b* color values of two different apricot varieties as between 52.1 - 56.9, 24.3 - 26.7 and 44.5 - 50.1, respectively. Discrepancies between data in the present study and the other researches could be the result of a wide variety of factors such as cultivar, environmental and Fig. 2—Drying curves of apricot pestils, expressed as percentage of remaining weight vs. drying time storage conditions of the apricot. The results of the physicochemical analysis of the (as malic acid) of the pestil samples produced from apricot pestil dried with different methods were given different fruits was changed between 0.06 - 6.25%17. in Table 2. The moisture contents of the apricot pestil The effect of processing conditions on HMF samples were between 13.12±1.35 - 14.39±0.41 content of the apricot pestil was firstly determined in gm/100 gm. The final moisture contents of apricot this research. While the lowest HMF content pestils were designated according to literature data, (13.62±0.78 mg/kg) was determined in microwave pre-treatments and organoleptic properties. It has also oven dried pestil, the highest HMF content been speculated that moisture contents at or below (45.64±1.29 mg/kg) determined in sun dried pestil. 15% (wet basis) for most fruits is a rather safe HMF content of vacuum oven dried pestil sample indication that there is no microbial or mould growth (19.39±0.26 mg/kg) was also lower than sun dried and the reaction rate of a number of other deteriorative one, significantly. When comparing drying times, the shortest value was observed in microwave oven reactions (sugar crystallisation, non-enzymatic drying and it was followed by sun drying and vacuum browning, flavour deterioration, lipid oxidation, etc.) 13 oven drying. Heat treatment applied for fruit is significantly reduced . It was determined in pre leather production often reduces the number of treatments that less moisture contents caused 7 original volatile flavour compounds of fruits, caramelisation reactions. Ekşi & Artık reported while introducing additional volatile flavor the moisture content of apricot pestil as 17.3%. While compounds through the auto-oxidation of unsaturated the moisture content of grape pestil was reported as fatty acids and thermal decomposition, and initiation 9 11.2±0.1 gm/100 gm , it was determined as 17.2% of Maillard reactions. The products of these reactions in mango leather10. Çağındı and Ötleş8 determined (mainly hydroxymethylfurfural-HMF) are characterized the moisture content as between 13.0 ± 0.25 - 18.3 ± by raised antioxidant potential. The newly formed 0.10 (%) in apricot pestil samples. Torley et al.44 Maillard products, besides increasing the antioxidant examined six fruit leathers commercially capacity, can reduce polyphenol oxidation by inhibition manufactured in Australia. Substantial variation of polyphenol oxidase. However, the reported effects in moisture (7.4 - 18.1%) and sugar content (31.9 - of Maillard products on human health are quite contradictory. They have been found to have mutagenic 62.0 %) of the samples determined. 22 Ekşi & Artık7 reported higher total sugar content of or antimutagenic activity . The destruction of pigment components and occurence of Maillard apricot pestil as 80.1%. Reducing and total sugar reactions may occur due to cooking and drying of contents of the samples were between 24.00±0.44 - pestil at high temperature17. The difference between 27.35±0.00 and 51.32±1.11 - 61.40±0.52 g/100 gm, 17 total phenolic matter content of the pestil samples was respectively. Şengül et al. determined total statistically significant. The phenolic compound and reducing sugars between 30.91 - 54.60% and concentrations of the dried pestil samples were higher 21.38 - 41.05%, respectively. Similarly, it varied from than the concentration of fresh apricot due to the 15 20.9 to 26.3% in pineapple leathers . moisture loss. The increase in total phenolics is The differences between the titratable acidity of the possibly due to the liberation of phenolic compounds samples were not significant. Titratable acidity from the matrix during the drying process. Drying 52 INDIAN J TRADITIONAL KNOWLEDGE, VOL. 13, No. 1, JANUARY 2014

Table 1—Results of the physicochemical analysis of the apricot dehydration methods lead to higher retention of fruit antioxidants better color, texture and higher Analysis Mean rehydration capacity, sun dried pestil had the highest antioxidant activity and was preferred for sensory Total dry matter (gm/100 gm) 21.39±0.1 attributes such as color, appearance and chewiness in Water soluble dry matter (gm/100 gm) 20.75±0.1 this research (Fig. 1). This result might be originated Total sugar (gm/100 gm) 14.62±0.63 from necessity of longer drying period for vacuum Reducing sugar (gm/100 gm) 6.56±0.13 47 † oven drying. Quintero Ruiz et al. emphasised that if Titratable acidity (gm/100 gm) 0.33±0.00 considered a functional food, fruit leathers should be pH 4.71±0.00 †† stored under refrigeration so as to minimize Total phenolic matter (mg GAE/100 gm) 60.34± 0.30 antioxidant activity losses. Minerals (mg/kg) Pestil is important sources of minerals. The amount K 3849±114.55 of minerals of pestil samples was higher because of Ca 245±12.73 increasing dry matter content. The differences Mg 101±3.53 between K and Mg contents of pestil samples were Zn 0.27±0.00 not statistically significant. Except from Mg and Zn, ††† Antioxidant activity (%) 46.52±0.10 the highest mineral values were determined in Color microwave oven dried samples. L* 65.77±0.18 The color of apricot pestil can be described as a* 21.97±0.34 yellowish orange and is a very important parameter in b* 49.90±1.74 determining consumer preference. Values of L*, a*, ∆Eab* 85.14±0.95 and b* after three drying methods applied were h° 66.14± 0.36 changed between 44.37±0.85-49.06±0.38, 16.22±0.52 C*ab 54.15±1.46 -20.81±1.07 and 33.81±1.64-41.76±1.22, respectively †: †† ††† citric acid GAE: gallic acid equivalent The extracts for (Table 2). Compared with raw apricot pulp, apricot antioxidant activity were tested at concentration of 8 mg/ml on leathers were darker (lower L* values). Drying dry basis. methods exerted a significant effect on the color might have accelerated the release of bound phenolic changes of pestil samples. L* (lightness) value of compounds during the breakdown of cellular samples decreased by after all drying methods. a* and constituents 45. Moreover, the long time required for b* values describes redness and yellowness of vacuum drying might have decreased the phenolic samples. Redness and yellowness were significantly content of vacuum oven dried apricot pestil. Şengül et higher in microwave oven dried sample. While the al.17 indicated that total phenolic content was found differences between a* values of the pestil samples from 4.79 (mulberry pestil) to 28.36 µg GAE/mg were not significant in sun dried and vacuum oven (plum pestil) which were very higher than the value dried samples, the differences between the values of found in apricot pestil samples. This difference could b* were not significant in sun dried and microwave 8 be originated from the fruit used, additives and oven dried samples. Çağındı and Ötleş reported that process conditions. L*, a* and b* values varied from 88.04 to 100.85, Retention of antioxidant activity of the sun dried, 10.26 to 12.85 and -6.33 to 13.27 in apricot pestil 17 microwave oven dried and vacuum oven dried samples. Şengül et al. also measured these color samples was calculated as: [100-(Antioxidant activity values as 27.35-41.35, 1.25-11.50 and 0.99-18.22, of apricot fruit-Antioxidant activity of the dried respectively. Total color difference (∆Eab*) and sample/ Antioxidant activity of apricot fruit*100)] chroma (C*ab) values of pestil samples also were and the values were found as 59.81%, 39.23% and changed between 64.32±0.89 – 58.38±1.79 and 46 19.15%, respectively. Demarchi et al. evaluated the 46.67±0.61–37.94 ± 1.76, respectively. ∆Eab* and influence of pretreatment on final product structure as C*ab values were found significantly higher in well as the effect of hot air drying on color and microwave oven dried pestil sample. o o antioxidant retention in apple leathers. Retention of The hue angle (h°) ranges from 0 to 360 , where antioxidant activity of apple leathers was low (6-16%) 0o is purplish-red and 90o is yellow48. h° value of all and decreased for increasing air temperatures even samples ranged from 63.01±0.24 to 67.06±0.23 when the resulting drying times were shorter. (Table 2 ) indicating somewhat yellowish color. The Although Orrego et al.22 reported that the vacuum highest h° value was determined in sun dried samples. SUNA et al.: IMPACT OF DRYING METHODS ON PHYSICOCHEMICAL AND SENSORY PROPERTIES OF APRICOT PESTIL53

Table 2—Results of the physicochemical analysis of the apricot pestil samples

Analysis Sun dried Pestil Microwave oven dried Vacuum oven dried pestil pestil Moisture (gm/100 gm) 14.39±0.41 13.25±0.28 13.12±1.35 Total sugar (gm/100 gm) 58.83±0.71a 51.32±1.11b 61.40±0.52a Reducing sugar (gm/100 gm) 26.14±0.35b 24.00±0.44c 27.35±0.00a Titratable acidity† (gm/100 gm) 0.69±0.00 0.81±0.00 0.75±0.00 Hydroxymethylfurfural (mg/kg) 45.64±1.29a 13.62±0.78c 19.39±0.26b Total phenolic matter (mg GAE/kg) 121.24±6.19a 120.06±1.16b 110.03±0.72c Antioxidant activity (%) 27.82±0.10a 18.25±0.32b 8.91±0.10c Minerals (mg/kg) K 14578.98±250.94 14981.34±30.36 14770.06±117.63 Ca 843.13±27.37c 1063.44±9.56a 950.68±12.51b Mg 439.06±1.99 419.26±13.60 414.48±1.69 Zn 6.89±0.91b 10.17±0.71a 12.00±0.67a Color L* 49.06±0.38a 47.47±0.08a 44.37±0.85b a* 16.22±0.52b 20.81±1.07a 17.22±0.66b b* 38.31±0.79a 41.76±1.22a 33.81±1.64b

∆Eab* 64.32±0.89b 66.57±0.36a 58.38±1.79c h° 67.06±0.23a 63.50±1.85b 63.01±0.24c

C*ab 41,60±0.93b 46.67±0.61a 37.94±1.76c †: citric acid †† GAE: gallic acid equivalent †††The extracts for antioxidant activity were tested at concentration of 8 mg/ml on dry basis

For sensorial test, panelists were briefed about the alternative to increase the commercial value of the properties of apricot pestil. The product should have fruit, particularly when there is an over production bright yellow color related with color of apricots, of the fruit during a season. It has long shelf life should not be burned or browned, while the typical and can be stored without deterioration. For the apricot taste and aroma should be appreciated. Pestil diabetic people, pestil made without sugar could be should not be stick on teeth and be easily chewable. a healthy preference as a snack and it has the Sun dried pestil sample was preferred for color, potential to increase fruit solids especially in the appearance and chewiness. However vacuum dried young. Economically feasible alternative pestil was selected for taste. All of the apricot pestil processing technologies, drying conditions and samples were generally acceptable by the sensory additives should be tested, in order to determine a panelists. suitable procedure for developing pestil while preserving their nutritional value. Apricot pestil is a Conclusion good source of energy and minerals. It can be an Consumption of fruits as a significant portion of alternative confectionary not only for children but daily diets has been associated with a lower risk of for adults as well. It is important to increase coronary heart disease and cancer49. Given the wide consumption of this nutritional and beneficial range of bioactive factors in fresh fruits preserved product as an alternative appetizer. in pestil, it is possible that their uptake have a It was determined that traditional sun dried apricot positive effect in reducing the risk of many pestil has a good nutritional quality and organoleptic diseases22. The consumer trend nowadays is characteristic compared to other samples produced towards more natural snack foods25. For this reason, by microwave and vacuum oven drying. However, the preparation method of this traditional product the improvement and standardization of this method should be defined, or standardized to inform in terms of hygiene, drying period and consumers and to favor trade at national and environmental conditions of product should be international level. Pestil production is an proposed. 54 INDIAN J TRADITIONAL KNOWLEDGE, VOL. 13, No. 1, JANUARY 2014

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