Plum Production Research Articles

Fruit self-sufficiency assessment in Bosnia and Herzegovina

Fruit is one of the essential products in the proper nutrition of the population. In the conditions of free trade, due to the great economic importance of fruits and fruit products, fruit foreign trade is subject to constant monitoring and evaluation of the production and consumption conformity. The aim of this paper is to analyze the volume, dynamics and structure of fruit production and consumption in Bosnia and Herzegovina (BiH) in the period 2014-2017, and point to the need for greater alignment of fruit production and consumption. Data from secondary sources were studied to determine the degree of self-sufficiency for apples, pears and plums, the three main fruit species in Bosnia and Herzegovina. Methodologically, the level of self-sufficiency was calculated using formulas recommended by FAO and the Laspeyres aggregated price index. The degree of self-sufficiency in apple is between 70% and 86%, depending on the year. Pear has the lowest production but slightly higher degree of self-sufficiency compared to apple (88-96%). BiH has a surplus only in plum, in both fresh plums and plum products, which means that the degree of self-sufficiency is higher than 100% by 2-5%. Given its geographical location and climatic conditions, BiH could produce more fruit than its current production, fully meet the needs of its population, and generate a surplus in its foreign trade.

Antioxidative Capacity of and Contaminant Concentrations in Processed Plum Products Consumed in Romania

The bioactive compounds (total phenols, anthocyanins, and flavonoids) and antioxidant activity of plum-based products (prunes, jams, and marmalade) were evaluated based on spectrophotometric assays and acrylamide and 5-hydroxymethyl-2-furaldehyde concentrations to determine the quality and safety of these products in the Romanian marketplace. The total polyphenol concentrations in prunes, marmalade, and jams were 0.93 to 5.63 g of gallic acid equivalent per kg of dry matter, and the antioxidant activity was 3.0 to 17.2 mmol/kg. The concentrations of potentially harmful acrylamide in the plum products ranged from the limit of quantitation (<20 μg/kg) to 37.44 μg/kg, and the concentration was higher in prunes (26.66 to 163.72 μg/kg) than in jams. The 5-hydroxymethyl-2-furaldehyde concentrations in plum products were also variable, at 36 to 2,149 mg/kg. These data revealed a very low concentration of acrylamide in thermally processed plum products, and the results for total polyphenols and the antioxidant activity of prunes and plum jams may be relevant for evaluating these products as important sources of bioactive compounds.

Soil Suitability Assesment for Plum (Prunus domestica) Production in the Municipality of Bužim

Amateurish and unprofessional handling of agricultural resources has lasting und unprecedented consequences for plant production, manifesting itself through the loss of soil quality, reduced crop yields, soil erosion, etc. The main focus of this research was to establish the characteristics of the agricultural soil within the municipality of Bužim, applying the FAO method AEZ (Agro-ecological Zoning), (FAO, 1978), and based on the achieved results, to assess the soil suitability for plum (Prunus domestica) cultivation. The assessment of the soil suitability has led to the conclusion that a significant part of land (classified S1 to N in quality), out of the total 13.026,27 ha of agricultural area belonging to the municipality of Bužim is well suited for fruit production. The following has been observed: areas with the best rated S1 class make up a total of 1.23% (159.52 ha), the S2 class takes up a total of 5.51% (717.24 ha), the S3 suitable class makes up a 2.29 % (298.24 ha) in total, and the largest area totaling 36.68 % (4.772.60 ha) is classified as N - meaning unsuitable soil. The main restraints imposed on intensive plum cultivation within the examined area are lack of nourishment, tilt, depth, rock-strewn soil and soil reaction.

Use of plant growth regulators in fruit nursery production of plums and sweet cherries

Use of plant growth regulators in fruit nursery production of plums and sweet cherries

Regionalna obeležja tržišne proizvodnje voća i grožđa u Srbiji

In the paper analyzes the trends in the development of market production of fruit (on the example of the apple and the plum) and grapes in Serbia from 1976 to 2015. The grouping of the Serbian districts according to the degree of the market production of fruit and grapes in 2015 was performed by a cluster analysis, on the basis of the six features of production, five features of the capacities, and five features of development. According to the data for 2015, the degree of the marketability of apples in Serbia was 47.7%, plums 15.9%, and grapes 18.3%. The Serbia-North Region shows a surplus in the production of apples, and a deficit in the production of plums (-181.7%) and grapes (-99.1%). The Serbia-South Region has a surplus in the production of the analyzed kinds of fruit (the apple accounting for 43.0%, and the plum 50.9%) and grapes (45.2%).

Evaluating Spatially Resolved Influence of Soil and Tree Water Status on Quality of European Plum Grown in Semi-humid Climate.

In orchards, the variations of fruit quality and its determinants are crucial for resource effective measures. In the present study, a drip-irrigated plum production (Prunus domestica L. “Tophit plus”/Wavit) located in a semi-humid climate was studied. Analysis of the apparent electrical conductivity (ECa) of soil showed spatial patterns of sand lenses in the orchard. Water status of sample trees was measured instantaneously by means of leaf water potential, Ψleaf [MPa], and for all trees by thermal imaging of canopies and calculation of the crop water stress index (CWSI). Methods for determining CWSI were evaluated. A CWSI approach calculating canopy and reference temperatures from the histogram of pixels from each image itself was found to suit the experimental conditions. Soil ECa showed no correlation with specific leaf area ratio and cumulative water use efficiency (WUEc) derived from the crop load. The fruit quality, however, was influenced by physiological drought stress in trees with high crop load and, resulting (too) high WUEc, when fruit driven water demand was not met. As indicated by analysis of variance, neither ECa nor the instantaneous CWSI could be used as predictors of fruit quality, while the interaction of CWSI and WUEc did succeed in indicating significant differences. Consequently, both WUEc and CWSI should be integrated in irrigation scheduling for positive impact on fruit quality.

The economics of plum production on small farming households

The aim of this paper is to calculate economic indicators in plum production, namely: profitability, cost-effectiveness and productivity of labor, and determine whether this production is economically viable. The profitability analysis and the calculation of other economic indicators relate to the period from 2014 to 2016. The highest profit in the production of plums was achieved in 2015, amounting to 5250 €/ha, in 2016: 3897.24 €/ha, and the lowest in 2014, when it was only 1800 €/ha. Plum production is profitable, and the coefficients show that the amounts of 209 RSD (in 2016), 107 RSD (in 2014) and 250 RSD (in 2015) dinars were gained for every 100 dinars invested in production. The coefficients of cost-effectiveness were as follows: 3.5 (in 2015), 3.09 (in 2016) and 2.07 (in 2014) show that the production of plums is economically viable. The productivity of labor in the production of plums was approximately the same in the observed period, i.e., for each 1 euro of invested work, 72 to 77 kg of plum have been produced.

Efficacy of ACC (1-aminocyclopropane-1-carboxylic acid) as a Chemical Thinner Alone or Combined with Mechanical Thinning for Japanese Plums (Prunus salacina)

Thinning is a labor-intensive and expensive, but important practice in japanese plum production requiring new thinning strategies. The purpose of this study was to evaluate a new chemical thinner 1-aminocyclopropane-1-carboxylic acid (ACC) on ‘Laetitia’, ‘Fortune’, and ‘African Rose™’. ACC was also combined with 6-benzyl adenine (6-BA) and in one season on ‘African Rose™’ with mechanical thinning using the Darwin 300™ or hand thinning during bloom. All the foliar applications were made when the average fruitlet diameter was 7–10 mm using a spray volume of 1000 L·ha−1 under slow drying conditions. Significant thinning effects were found in all the trials conducted over the two seasons. ACC consistently reduced the hand-thinning requirement at commercial hand thinning in both seasons in ‘African Rose™’. In the second season there was a linear decrease in yield and an increase in fruit size as the ACC rate increased from the low to medium rate before flattening off. The combination treatment of ACC and the Darwin 300™ used in the ‘African Rose™’ trial thinned more aggressively, improved fruit size and shifted harvest earlier. The yield however was not lower than that of the control treatment. 6-BA was included in all trials to prevent ACC-induced leaf drop, and generally did not thin fruitlets, except in the case of ‘Laetitia’ where the combination with ACC resulted in stronger thinning. Cultivars differed in their sensitivity to ACC and the rate for each cultivar should be determined separately. The recommended ACC rate for ‘African Rose™’ would be 600 µL·L−1 and for ‘Laetitia’ 400 µL·L−1. For ‘Fortune’ a rate recommendation is not possible at this stage, thus further trials should be conducted. No broken stones were observed in fruit in any trial. Also, no leaf drop/phytotoxicity was recorded in any trial when ACC was applied during cool, slow-drying conditions.

Tam Hoa plums (Prunus salicina) in the maize-based system in the North-West Highlands of Vietnam

Tarn Hoa plum is one of three hybrids of the Japanese plum (Prunus salicina), originating from southern China, and grown between 700 and 1000 m altitude in north-west Vietnam for the domestic market. Along with some leguminous crops grown in rotation with maize, plums are an important source of additional income for smallholders. The aim of the project was to develop competitive value chains for plums with high levels of smallholder engagement. The research design was both structured and adaptive, based on participative action research. In addition, sensory evaluation to determine optimum measurable indicators of ripeness (soluble solids and hardness) based on consumer preferences was conducted to adjust time of harvesting. The research found that Tarn Hoa plum production and marketing is a large, complex system that is interconnected with the marketing of green (immature) plums to China and other substitutable fruit such as lychees, longans and other plums. It is a highly opportunistic, low-input system the outputs of which depend on plum prices, the relative production capability of districts and local microclimates. The 40- to 45-day plum harvest season is highly variable regarding harvesting dates, harvest duration, plum quality and, consequently, market prices. It was established that there is sufficient profit margin for all chain participants to establish a sustainable niche value chain based on high-quality sweet plums if reliable and sufficient throughput can be achieved. It is recommended that future similar value chain projects pay particular attention to selecting large 'aggregators' and 'distributors' so as to achieve volume and stable market access.

Physicochemical properties of whole fruit plum powders obtained using different drying technologies

Physicochemical quality parameters of plum powders obtained by applying conventional drying methods and their combination devised to process plums were evaluated. The effect of freeze-drying (FD), vacuum drying (VD), convective drying (CD), microwave-vacuum drying (MVD) and combination of convective pre-drying and microwave finish-drying (CPD-MVFD) affected physical (bulk density, porosity, colour, solubility) and chemical (polyphenolic compounds determined by UPLC and antioxidant capacity by TEAC ABTS and FRAP methods) properties of plum powders. The MVD at 1.2Wg−1 and a novel combination for plum powders production – CPD-MVFD at 70°C/1.2Wg−1 allowed the best preservation of phenolic compounds and increased the efficiency of production. Results obtained support the use of MVD and its combination for better quality of dried plum products. The study proved that the determination of the browning index and HMF level (formed via Maillard reaction) might be good tool for monitoring the thermal processing of plum powders.

THE IMPORTANCE OF AGRICULUTURAL PRODUCTION IN THE VALJEVO AREA IN THE DRINA BANOVINA 1929-1941

Agricultural production of the residents of the region of Valjevo is observed through farmers’ debts, and agricultural and social structure of the peasantry of the Valjevo area. The subject of this paper was the analysis of farm sizes, arable lands in the Valjevo area, population structure that made their living in agriculture and tillage machines used for cultivation of the land. The aim of the paper was to compare the branches of agriculture – livestock breeding and agronomy, and quantity and quality of residents’ agricultural products in the Valjevo area in relation to the Drina Banovina and the Kingdom of Yugoslavia. Special attention was paid to the analysis of fruit growing, primarily the production of plums, because the Valjevo area was the most significant producer of plums in the country.

Studies on dehydration of plum using different sugar syrup treatments

Being highly perishable plums cannot be stored for longer period at ambient condition and only 10 per cent is being processed. There is greater scope and necessity of developing an appropriate technology for drying of plums with long shelf life. Plums are produced around the world, and China is the world’s largest producer, The total plum production (of the 10 th largest producers) of plum was 9,921,953 MT in 2011. The ripe plums were treated at 100°C for 1 min in boiling water to deactivate the enzyme. The blanched fruits were dipped in sucrose, glucose, fructose and invert sugar syrups at 68°Brix, 72°Brix, 75 ° Brix for 24 hrs for getting desired total soluble solids content. The treated fruits were further dried to 20 per cent moisture in a tray dryer at 60–65°C. Good quality and acceptable dried plums could be prepared by using sucrose syrup treatment at 75°Brix.The chemical analysis of sucrose syrup treated at 75 o brix fresh plums and dehydrated plums were carried out with respect to carbohydrate, protein, fat, fibre and ascorbic acid content. No significant loss of nutrient was obtained due to osmotic dehydration. Dried plums prepared using sucrose syrup and packed in aluminium foil pouch and stored at ambient (27 ± 2°C) as well as refrigerated (10 ± 2°C) temperature, organoleptic evaluation shows that plum remained in excellent condition up to 3 months.

Acrylamide content and antioxidant capacity in thermally processed fruit products

Acrylamide as a known processing contaminant was determined in various heat-treated plum products purchased from a local market using LC/ESI-MS-MS. The highest level of acrylamide in the range up to 60 μg/kg was detected in a plum stew known as a "povidla", and in prunes, respectively. These products typically undergo intensive heat treatment that may take from several hours to days. Using a fruit dehydrator in home production of prunes, a low level of acrylamide under LOQ (15 μg/kg) was detected in comparison to most commercial products. Only in one of the prune samples from the market was the acrylamide content near to LOQ. The highest content of acrylamide (46 μg/kg) was detected in the Slovak sample of prune originated in Nitra region. High acrylamide content, in the range from 23 to 45 μg/kg, was observed in prunes from South America. In the rest of analysed heat-treated plum products such as plum juice, plum compote or baby food with plum puree, acrylamide was not detected due to moderate conditions during thermal processing: temperature below 120 °C and a shorter time of thermal exposure. The total phenolic content and antioxidant capacity of prunes were analysed using a UV-VIS-NIR spectrophotometer and an electron paramagnetic resonance (EPR) spectroscopy. Home-prepared prunes were characterized by the highest content of phenolics (4780 mg GAE/kg) and antioxidant capacity (14.6 mmol TEAC/kg). Commercial samples of prunes reached phenolics in the range from 1619 to 3461 mg GAE /kg, and antioxidant capacity was observed between 6.1 and 12.1 mmol TEAC/kg. Antioxidant capacity of prunes strongly correlated with total phenolic content and yellow and red colours measured in a CIELab system. However, no significant correlation between the acrylamide and antioxidative or organoleptic properties of prunes was observed. Moreover, it was noticed that bio production of plums did not demonstrate any positive impact on final acrylamide content or antioxidant capacity in comparison to conventional technology.

Changes of Bioactive Compounds and Ethylene Production of Japanese Plums Treated with Pre-Harvest Aminoethoxyvinylglycine

The effects of pre-harvest aminoethoxyvinylglycine treatments on bioactive compounds, fruit ripening, and quality of plum fruits (Prunus salicina Lindell cvs. “Black Beauty,” “Black Amber,” and “Friar”) were investigated in this research. Whole trees were sprayed once with an aqueous solution containing aminoethoxyvinylglycine (0, 100, and 200 mg L–1) two weeks before the anticipated commercial harvest for each cultivar separately. In all plum cultivars, the results showed that aminoethoxyvinylglycine treatments were effective in reducing ethylene production and respiration rate. The red color development was delayed by aminoethoxyvinylglycine treatments during the ripening. The fruit mass and geometric mean diameter significantly decreased, while loss of flesh firmness was decelerated with aminoethoxyvinylglycine concentrations. Aminoethoxyvinylglycine treatments decelerated loss of flesh firmness. Soluble solid content was reduced, whereas titratable acidity and ripening index increased with aminoethoxyvinylglycine treatments. Aminoethoxyvinylglycine-treated fruits exhibited lower levels of total phenolics, total antioxidant activity, and individual phenolics. This study revealed that pre-harvest aminoethoxyvinylglycine treatments were more effective in delaying plum fruit softening. The main advantage is to maintain the firmness of late-harvested fruit by retaining bioactive compounds of plum fruit.

The competitiveness of agricultural products: Case study of plum production and sale

The presented analysis of basic agricultural products, on the example of the fruit growing sector (the case study of plum), with quantitative data on the marketing channels subjects level, points that in the family-owned farms the most common goods turnover is the natural consumption aimed to satisfy own needs, with a low level of marketability and competitiveness. As a measure of success and development of Serbia's agriculture, the data of the fruit growing sector's marketability (the case study of plum) are presented, i.e. the average rate of movement, the manifestation of the variance coefficient around the computed average value of a given activity of the marketing channels. The small agricultural properties have a scattered production, an insufficient sale structure, and the present marketing channels fail to realize a safe placement of the seasonal products. In this research the recommendations are presented for achieving agro competitiveness and a higher export orientation.

Morphopomological Study of some new Japanese plum (Prunus Salicina Lindl) cultivars grown in Iran

Japanese plum (Prunus Salicina Lindl) is one of the most important plums in the world for fresh marketing. Successful plum production requires cultivars well adapted to the specific growing conditions in the area of production. Due to the interaction between environment and genotype in different species, preliminarily evaluation of agronomical and pomological performance for newly released cultivars in the areas where they will be cultivated is necessary. During the period 2012–2013, the suitability of 18 Japanese plum cultivar and genotype for cultivation, evaluated in Horticultureal Research Station (Karaj-Iran). 31 morphopomological traits such as bloom start and end date, ripening time, vegetative growth, trunk section area, internode length, vegetative bud size, leaf, fruit and stone size, flesh diameter, fruit and stone weight, TSS, TA, fruit texture, stone clinging, pH, dry matter and yield in two year were studied. The experiment was conducted in a Complete Randomized Design (CRD). Analysis of variance indicated that the cultivars were significantly different (P≤1%) for all traits. Cluster analysis classified cultivars into 5 main groups and 1 independent cultivar. The earliest cultivars ‘Black Star’ and ‘Morittini’, mid season ‘Shiro’, ‘Simka’, ‘No.16’, ‘Friar’, and the late one ‘Angeleno’, were most suitable and recommended for cultivation in Iran.

Influence of fermentation conditions on production of plum (Prunus domestica L.) wine: A response surface methodology approach

Plum (Prunus domestica L.) is the most important and most commonly grown fruit species in Serbia, one of the leading plum-producing countries. It is mainly used for table consumption, drying and fruit brandy production. The use of plums for wine production is not sufficiently investigated. The aim of this study was to investigate the influence of temperature, pH and duration of fermentation on the plum wine composition and quality, and to optimize these factors by response surface methodology (RSM). Second order polynomial equations, which represent fitted models for investigated responses, are shown as adequate (R2 &gt; 0.90 and P &lt; 0.05). The average values of ethanol and glycerol content in plum wine were 6% and 5 g/L, respectively, while high methanol concentrations (above 1000 mg/L) were recorded in all wine samples. This requires further investigation of possible procedures to reduce the methanol content in the wines, according to its toxic properties to human. Optimal conditions for plum wine production, obtained with the application of RSM, were 18.3 ?C (temperature), 3.0 (pH) and 7 days (fermentation time). Apart from the problem of very high methanol concentrations, plum wine produced with the optimal conditions had good sensory properties and acceptability.

Evaluation of Two Levels of Plum Concentrates as an Alternative to Polyphosphates in Post-Harvest Preservation of Ictalurus punctatus X I. furcatus Catfish Fillets

Marinades made of water, salt, and phosphates have been applied to fish fillets to bind water, to prevent lipid oxidation, extend shelf-life, and to control freezer burn (frozen fillets). Recently plum products have been employed as marinades in poultry, beef, and pork products: pectin acids contribute to moisture retention, malic acids enhance flavor, sorbitol is a humectant, and phenolic compounds contribute to the antioxidant properties which slow lipid oxidation and improve human health. Hybrid catfish fillets were vacuum-tumbled to attain either a 0.45 or 1.0% level of plum extracts. Pickup minus drip loss after 24 h was 11.81%, and pH 6.82 at the 0.45% level and 14.60% and 6.73 at the 1.0% level. Fillets were slightly redder/pink. These results are comparable to those achieved with the conventional polyphosphate marinades without additional salt and phosphates and with added beneficial antioxidants.

Physical and Chemical Properties of Some European Plum Cultivars (&lt;i&gt;Prunus domestica&lt;/i&gt; L.)

Fruits from twelve plum cultivars (Prunus domestica L.), were analyzed in terms of physical and chemical characteristics. The fruits trees were grown in a trial at University of Craiova - Fruit Growing Research Station (SCDP) Valcea, which is located in Bujoreni, an important Romanian plum production area. Fruits were picked at harvest maturity. Several analyzes were performed, such as fruit linear dimensions, size index, fruit weight, dry matter, soluble solids content, titratable acidity, total anthocyanins, malic, tartaric and citric acids content. The best features in terms of physical and chemical properties proved to be found in ‘Alina’, ‘Alutus’, ‘Tuleu Timpuriu’, ‘Oltenal’ and ‘Renclod Althan’.

Changes after high-pressure processing on physicochemical parameters, bioactive compounds, and polyphenol oxidase activity of red flesh and peel plum purée

Physicochemical parameters (instrumental color, soluble solid content, titratable acidity, and pH), bioactive compounds (total phenols and anthocyanins), total antioxidant activity, and enzymatic activity of polyphenol oxidase (PPO) were evaluated after the application of hydrostatic high-pressure (HP) treatment on a plum purée (cv. Crimson Globe, with red flesh and peel). Different pressure levels (400, 500, and 600 MPa) were applied at different processing times (1, 150, and 300 s). HP-treated purées were compared with the untreated purée. The inactivation of indigenous microorganisms (total aerobic mesophilic and psychrotrophic counts, and molds and yeasts) of the plum purée after all high-pressure treatments was sufficient to reduce spoilage microorganisms present in plum purée to undetected levels in most of HP-treated purées. No significant changes were observed in pH and soluble solid content after processing. The combined treatments (pressure level and processing time) did not reach a sufficient inhibition of PPO enzyme. Processing induced a significant increase in L*, a*, hue, and chroma, which could enhance the redness perception of treated purées. All HP-treated purées showed a slight reduction in anthocyanins and antioxidant activity after processing. Nevertheless, total phenols were not significantly affected by HP-treatments. In conclusion, high-pressure processing keep most quality parameters and nutritional compounds levels, although, it did not achieve the inhibition of browning related enzymes, which could reduce the shelf-life of plum products during storage. High-pressure processing is one of the most successful technologies to obtain high-quality fruit purées. However, the application of this technology to certain products presents some difficulties due to high-pressure and usually does not affect the activity of browning related enzymes. The present study evaluates the effect of high-pressure treatments on the color, bioactive compounds, and polyphenol oxidase enzyme of plum purée. This is one of the first studies about the application of high pressure technology for the preservation of red flesh and peel plum. High-pressure treatments did not achieve the total inactivation of the polyphenol oxidase enzyme, however, total phenols and anthocyanins were well preserved after the treatments. Our results also show that redness and color luminosity of plum HP-treated purées were well retained. Therefore, high pressure processing offers the opportunity to processing plum purée with fresh-like properties. Nevertheless, the storage of the product could be limited due to the lack of effect of the pressure on the enzyme activity.