Volume 22(2), 95- 99, 2018 JOURNAL of Horticulture, Forestry and Biotechnology www.journal-hfb.usab-tm.ro

Characterization of the main Romanian varieties based on pH, refractometric index and moisture content

Bogdanescu Dana1, Bordean Despina-Maria1, Poiana Mariana Atena1, Hadaruga Nicoleta1, Tataru Oana1 And Rivis A.1

1Faculty of Food Processing Technology, University of Agricultural Sciences and Veterinary Medicine of Banat "King Mihai I of Romania" Timisoara, 119 Calea Aradului, 300645 Timisoara, Romania

*Corresponding author: [email protected], [email protected]

Abstract are the most fresh fruits consumed in our country Key words throughout the year, being also a valuable raw material for the production of marmalades, jams and compotes or juices, and other alcoholic autochthonous and actual beverages or apple vinegar including dehydrated fruits, such a fruit with apple , special dietary qualities is recommended for the nourishment of children and characteristics of apple, sick people. To determine the characteristic appearance in some native Romanian apple like , Starkrimson, Boiken, , Rennet Cenusiu, Varatic, apples, pH, Refractometric Index and moisture content were determinate. Water content in fruits is an important factor which influences quality of fruits. The choice of apple varieties used to produce cider is very important and one of the most important features is pH. The paper contributes to the efforts focused on saving of genetic variability of Romanian apples and their further application both in human nutrition and a further breeding and selection under conditions of pomological and alimentary practice.

Apple is a fruit cultivar that is mostly taken fresh and it storage diseases. Harvesting apples is done manually, ripens from late summer to winter. Apple is the most with a peduncle, without pulling out, by a slight twist common species, like plum of fruit tree cultivated in of the fruit, preventing it from blows or injuries. From our country. Basic factors of quality that most the time of harvesting until the introduction of the fruit researchers mention are: size, shape, color, taste, scent into the storage area, it must not be longer than 2-3 [1, 5, and 7]. days, in order not to negatively influence the storage The biochemical composition specific to apples, capacity. For long-term storage should be selected only relative to the main components (mean values) is fruits of high economic value varieties such as Golden characterized by: Carbohydrates (12-14%), Fatty acids Delicious, Jonathan, Starking Delicious, Strakrimson, (0.7-1%), Pectic substances (0.7-1.2%), Cellulose Florina, Idared, Reinett etc. The optimum storage fibers (2.1%), Mineral substances (0.32%), Vitamin C temperature varies with the variety or group of varieties (5-10 mg / 100g fresh product). and, depending on their sensitivity to low temperatures Physical characteristics of apples are: the firmness of which might cause physiological disturbances (intense the pulp, and content of the soluble substance, which browning, anaerobic respiration). can be determined by refractometry and/or biochemical Cold-resistant varieties with sweet and acid-free fruits (starch test with iodine in potassium iodide). As apples such as Golden Delicious, Starkrimson ripen, starch is converted to sugars. In the starch test, etc. are kept at 0° C + 1° C. Acid varieties, more iodine binds with starch granules in the fruit and sensitive to cold, cling to a temperature of 3-4° C. This develops into a dark purple to almost black color; the category includes Jonathan, Wagener award, Idared, less iodine development (less dark purple color). Renet, . These temperatures must be Several visual rating scales have been developed to reached within 1 week and the allowed oscillation assist to rate the various degrees of starch development. limits will not exceed ± 1° C. To prevent the The color chart is located in the centerfold and is often physiological disturbance of cold-susceptible varieties, referred to as the Cornell Starch-Iodine Chart [8, 15]. If modern technologies provide for the first part of their the fruit is harvested too early, it does not achieve a storage an optimum 3-4° C temperature, after which, in perfect maturation, especially organoleptic, and the second part of storage time, the temperature sensitization to the bitter pit becomes bitter and decreases to +1.5° C - + 2° C, to prolong the shelf life, specific burns. Also, the delay in harvesting leads to without causing further negative effects. The relative the emergence of risks to stored fruits, which accelerate humidity of the air will remain within the optimal 90- maturation and become sensitive to manipulation and 95% range for all varieties, and air circulation will rise

95 to about 0.25 m / s with a 30 recirculation per hour. Determination of Refractive Index The economic retention period is 5 to 7 months, the Refractive index (RI) was measured using an ATC varieties in the Jonathan group standing on the lower Refractometer Brouwland Belgium.With the help of limit. refractometer sugar concentrations in apple juices was Materials and Methods measured and the Refractive Index was displayed instantly. The study was conducted in the period 2015-2017 to assess the influence of apple‟s varieties characteristics, Determination of pH maturity and origin on the fresh consumption, juice, For pH measurements was used a Radelkis Budapest – cider processing Precision Digital pH Meter type OP 208 and Hanna Instruments HI 7004 as calibration solutions. The Collection and preparation of apple fruit samples electrical potential was measured between the pH Eight medium–apple varieties available in Romania electrode and the reference electrode, and the pH was were used to determine refractometric index and pH registered. fermentation varieties: Varatic (VR), „Jonathan” (JO), Starkrimson Delicious, Double Red (SD), Florina (FL), Determination of moisture Idared (ID), Boiken (BK), Golden Delicious (GD), Moisture determination was performed by Renete Cenusiu (RE). The fruits were harvested, thermogravimetric analysis of the samples using the transported to the laboratory unit and stocked at room Sartorius thermo balance [2]. temperature - around 20 °C - just to the maxim maturation degree–this procedure is used by local Statistical analysis producers to obtain the maximum levels of fermentable Statistical analysis was performed using the statistical sugars. Treatment consists of washing fruits with tap software program PAST version 2.17 [4]. water and gently drying with filter paper. Then, apples were selected according to uniformity of shape and Results and Discussions color, and prepared for analysis. Fruit weight, moisture, Refractive Index and pH were determined by using In figure 1 are presented the apples varieties selected fresh fruit samples. for preparing cider based on the pH value and Refractometric Index (sugar content). The characterization offers also a better look regarding the apples available in Romania.

“Starkrimson Delicious, “Florina” Apple, „Varatic” Apple “Jonathan” Apple Double Red“ Apples, Caras Severin Areea,

Golden Delicious Apple, “Renete Cenusiu” Apple “Boiken” Apple “Idared” Apple Caras Severin Area, ( grise) Baia Sasca Montana Area Sanicolaul Mare Mare Area Fig. 1. Studied Apple assortments (photos Dana Bogdanescu)

The characterization of the apples presented in figure 1 Fruit characteristics: small or medium sized, spherical, resumed one by one, based on their sweet content, with irregular contour: the background color is lemon- flavor, and appearance and consumption maturity: yellow, the pink cover in the form of long and thin  „VARATIC” Apples stripes, with many small whitish spots on the exposed Origin: Republic of Moldova [3]. side of the sun. Skin is thin, adherence to the pulp,

96 smooth gloss, wrinkles of different sizes. Creamy, soft Fruits with high storage capacity retain their fruity and juice is succulent, grainy, and slightly aromatic; sweet tasteful qualities until April-May. taste; used as table fruit for pies and flesh. Consumption maturity: from December to March- Consumtion maturity: end of July to late August and on April, sometimes even more; high hills is extended until mid-September;  “BOIKEN” Apple from Sasca Montana  “JONATHAN” Apples Origin: Bremen, Germany, introduced in 1828 or Origin: New York prior to 1826 [6]. earlier [9]. Fruit characteristics: medium or over mold, fairly Fruit characteristics: The features of the medium or evenly on the same tree. The truncated conical shape, large fruit, the asymmetric five-shore shape are very rounded at both ends, is regular and almost pronounced. The background color is yellow green at symmetrical. The yellowish lemon background color harvest, at the strawberry mature maturity, the reddish- with a light greenish hue is covered on all the red brown covering on the exposed side of the sun, with bloody red fruit. Smooth, elastic skin is squeezed under characteristic gloss, many small whitish spots or rust improper storage conditions. The pulp is greenish color are distributed over the entire surface of the fruit. yellow, cream yellow or darker yellow in the heart The skin is thick, smooth, covered with abundant, area. Sweet succulent taste slightly acidified strongly glossy, aroma-free. The white pulp, the medium aromatic; use of table fruit or preserved for a long time. consistency is fine, succulent, and after maturity it Consumption maturity: from November to April; becomes flour and a slice; refreshing, strong chewing,  “STARKRIMSON DELICIOUS DOUBLE sweet, slightly aromatic. Used mostly as table fruit, for RED“ Apples from Sannicolau Mare drying, marmalade and/or apple jelly. Origin: United States, Introduced: 1870 [13]. Consumption maturity: from December to the end of Fruit characteristics: large or large fruit, weighing May; 130-300 g, 180-350 g shape conical truncated,  “GOLDEN DELICIOUS” Apples from strangulated to the top, flattened at the base, with five Caras Severin Area and Sannicolaul Mare ribs, the surface of the trunk is very rarely smooth, the Origin: West Virginia, United States, introduced in greenish yellow color is covered with the reddish color 1890 [11]. on the entire surface of the fruit, especially the sun Fruit characteristics: the fruit of variable varieties of exposed, over which overlapping short, dark, dark, the same conical shape, relatively narrow, truncated dark carmine stripes. Under the skin there are many and swollen at the base and narrow rounded to the top, white dots. The skin is thick, hard, luscious, covered with five distinctly different ribs. The yellowish green with rusty purple, very abundant. The yellowish pulp, background is very lightly covered on the sun-exposed with weak red infiltrations, immediately under the skin, side with orange rum, with purple beauties. Under the is quite dense, sometimes crisp. It is very succulent, skin there are brown rust points, surrounded by dirty sweet with pronounced flavor, but devoid of acidity. green aureoles. Skin is hard, smooth, and adherent to Consumtion Maturity: end of November to February; the pulp, covered with an abundant layer of pruine.  “FLORINA“ Apples from Caras Severin Yellow, crispy, slightly elastic, succulent taste is very County sweet, slightly acidified, the finely cantaloupe, Origin: it is a new variety obtained in Angers, France pronounced, specific to the variety. By keeping it loses in 1977 and introduced and licensed in Romania in its acidity, it becomes very sweet; frost-resistant fruits. 1993 [10]. Consumption maturity: end September to March; Fruit characteristics: supermodel or large fruit,  “RENET CENUSIU” Apples (Fr: Reinette spherical or frustum spherical; the background color is grise) from Baia Mare Area yellow, covered with red aniline, with white whites all Origin: Normandy, France; introduced in 18th century over the surface. The pulp is creamy consistent.Taste and for the first time described in 1771 [12]. sweet and slightly acidic, pleasantly aromatic. Fruit characteristics: the fruit is large or very large, Consumption maturity: from November to March; truncated conical shape, lower, narrower to the top and  “IDARED” Apples very flattened at the base; has five very wide and Origin: The University of Idaho developed Idared in rounded ribs. The green dirty background at the time of 1930, and released it to market in 1942 [14]. harvesting turns greenish to full maturity. The skin is Fruit characteristics: The fruit is medium to large (180 thin, hard, mature, without bruising, and hard to touch, g), spherical or spherical, smooth, regular, slightly half the pulp. The pulp is initially white-green and then costlier. The skin is smooth, the background color is becomes yellowish, with the wedding to orange; is yellowish yellow to yellowish white, striated and crisp and soft as it progresses in storage. Taste: fine, washed on ¾ of the surface, with light red, very aromatic, succulent, sweet and pleasantly acidified, attractive. The pulp is white, slightly yellowish, crisp, ducks the optimum consumption, becomes crisp and smooth, sweet-sour, slightly aromatic. Variety loses its qualities; Used as table fruit or for drying. qualities: Early fruit entry, large and constant Consumption Maturity: November to December, productions. It is suitable for high density culture. January; sometimes they can be kept until March, April.

97 The values presented in table 1 and figure 2 shows the content). Analyzing the pH values it is observed that characteristics of the apples based on their studied the lowest pH occurs at Rennet (3.28) and the highest parameters (Refraction Index, pH and moisture at Florina (4.2).

Fig. 2. Refraction Index, pH and moisture content of studied apples Legend: Varatic (VR), Jonathan (JO), Starkrimson Delicious, Double Red (SD), Florina (FL), Idared (ID), Boiken (BK), Golden Delicious (GD), Renete Cenusiu (RE)

As is known from the literature and practice, the pH of content and was determined for Golden Delicious used for cider production must not be (15.30) while the smallest is 10.30 for Idared. A high greater than 3.6. This is why the choice of apple sugar content allows a higher concentration of alcohol varieties used to produce cider is very important and in the final product.The highest moisture content is one of the most important features is pH. The largest presented by Idared and the lowest by Golden RI is directly correlated with the fermentable sugar Delicious.

Fig. 3. Cluster Analysis of the studied parameters values Legend: Varatic (VR), Jonathan (JO), Starkrimson Delicious, Double Red (SD), Florina (FL), Idared (ID), Boiken (BK), Golden Delicious (GD), Renete Cenusiu (RE)

98 Cluster analysis based on Euclidian Distances using References Paired Group Algorithm (figure 3) groups the apples assortments into 3 groups: one group GD, SD, BK and 1.Abbott J.A., Saftner R. A., Gross K. C., Vinyard B. VR, second group formed by RE, JO and FL and third T., Janick J. (2004). Consumer evaluation and quality group, a group that is including only Idared (ID), based measure-ment of fresh-cut slices of „‟, „Golden on the moisture content associated to pH and RI. Delicious‟,„GoldRush‟ and „‟ apples. Postharv. Biol. and Techn. 33: 127–140; Apples Use Recommendations 2.Bordean, D.M., Borozan, A.B., Cojocariu, L., Moigradean, D., Cojocariu, A., Nica, D., Pirvulescu, As the structure and texture of apples, and the ratio of L., Alda, S., Horablaga, M., Seasonal variation in the chemical compositions, the taste and aroma vary nutrient content of some leafy vegetables from Banat from one variety to another, different varieties are county, Romania, (2013), Review on Agriculture and suitable for processed apple products. Thus: for drying Rural Development, V.2.(1):170-174, http://leto.mgk.u- and smoking match Boiken, Golden Parmen, for szeged.hu/RARD/2013-1/30- transformation into marmalade, jelly, are recommended 13_Despina_Maria_Bordean.pdf; the native apple varieties, which have an appreciable 3.Cvetković, M., Tomić, L., Botu, M., Gjamovski, V., content of dry substance, high acidity and pectic Jemrić, T., Lazović, B., Ognjanov, V,.... & Bozovic, substance but also a strong aroma; for the preparation D., (2012). Balkan Pomology: Apple. Exactaprinting of high quality juice and acid it is required that the fruit AB. contain at least 14% of total sugar, 0.8% of acidity, https://www.researchgate.net/profile/Lidija_Bitz/public 0.15% of tannic solids and 15% of dry substances [15]. ation/233389784_Balkan_Pomology_Apple/links/0a85 For juice and cider it is recommended Boiken, Frumos e535e1a9b2d83d000000/Balkan-Pomology-Apple.pdf; de Boskoop, Renet Cenusiu, Renet of Canada. These 4.Hammer, Ø., Harper, D. A. T., & Ryan, P. D. (2001). varieties contain the right quantities of dry matter, Paleontological statistics software: package for sugar, acidity and pectic substances. The compote is education and data analysis. Palaeontologia used for all apple varieties that have a firm structure Electronica, (4). and texture, a pronounced aroma and an open pile of 5.Harker, F.R., Marsh, K.B., Young, H., Murray, S.H., color. The most used are Parmen, Golden and Boiken. Gunson,F.A. and Walker, S.B. (2002). Sensory interpretation of instrumental measurements 2: sweet Conclusions and acid taste of apple fruit. Postharvest Biology and Technology, V. 24: 241-250; 6.Maple Valley Orchards, LLC, Suamico, 2018, Domestic apples are normally sold only with the name http://www.maplevalleyorchards.com/pages/AppleTree of the cultivar with no other information (and Descriptions_J.aspx?page=J; sometimes not even the name is shown). Well branded 7.Skendrovic M., Babojelic M., Ivancic K., DruzicJ., and correctly presented domestic apples of premium Kovac A., Voca S. (2007). Chemical and Sensory quality would create added value in the fruit and Characteristics of Three Apple Cultivars ( x vegetable sector and that is why it would be advisable domestica Borkh.), Agriculturae Conspectus to give more information regarding weight, pH and Scientificus, , Vol. 72 (4): 317-322; moisture content of apples. 8.https://blogs.ext.vt.edu/tree-fruit- horticulture/2012/08/23/harvest-maturity-resources; Acknowledgements 9.https://www.orangepippin.com/apples/boiken; 10.https://www.orangepippin.com/apples/florina; The results of this research will be included in the PhD 11.https://www.orangepippin.com/apples/golden- Thesis of Dana Bogdanescu, PhD student at Banat‟s delicious; University of Agricultural Sciences and Veterinary 12.https://www.orangepippin.com/apples/reinette-du- Medicine “King Michael I of Romania” from canada; Timisoara. 13.https://www.orangepippin.com/apples/starkrimson; 14.http://www.specialtyproduce.com/produce/Idared_ Apples_13181.php; 15.http://www.uvm.edu/~fruit/treefruit/tf_cider/Calvi WLCider033015.pdf.

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