Nutritional Values of Minikiwi Fruit (Actinidia arguta) after Storage: Comparison between DCA New Technology and ULO and CA.

The dietary properties of minikiwi make them, along with other fruits and vegetables, suitable as the basis for many slimming and pro-health diets. Prolonging the availability of minikiwi can be provided by different storage technologies. This experiment focused on evaluating the effect of various O2 and CO2 concentrations, i.e., low-oxygen atmosphere (DCA, 0.4% CO2:0.4% O2; ULO, 1.5% CO2:1.5% O2) or high-CO2 (CA, 5% CO2:1.5% O2) storage, in order to provide the consumer with fruits with comparable high nutritional values. Evaluation gave the basic characteristics of the fruits that characterize their health-promoting properties, i.e., total polyphenols (TPC), phenolic acids and flavonols, antioxidant activity (AA), monosaccharides, and acid content. The atmosphere with a higher CO2 content of 5% (CA) effectively influenced the high value of ascorbic acid even after 12 weeks of storage. DCA technology contributed to a significant inhibition of phenol loss but not as effectively as CA technology. In contrast, glucose and fructose contents were found to be significantly higher after storage in ULO or DCA, while sucrose content was more stable in fruit stored in CA or DCA. CA technology conditions stabilized the citric acid content of minikiwi, while DCA technology was less effective in inhibiting acid loss. The nutritional value of the fruit after storage in CA or DCA was not significantly reduced, which will allow the supply of fresh minikiwi fruit to be extended and provide a valuable component of the human diet.

Assessment of the impact of innovative fertilization methods compared to traditional fertilization in the cultivation of highbush blueberry.

The aim of the research was to evaluate fertilization technologies for the indicators of the quality and quantity of highbush blueberry yield. In the experiment, a similar level of mineral fertilization was used in all treatments. The experiment was to show the differences between fertilization with biostimulation and without biostimulation. The research was carried out in two seasons (2019-2020) on ´Bluecrop` shrubs growing in the Blueberry Experimental Field in central Poland (51° 55'42.7 "N 20° 59'28.7" E). Shrubs grow at a distance of 1 x 3 m. Plants are rejuvenated every year in spring and irrigated by drip. The experiment was carried out in a random block design (4 fertilizer treatments x 5 replications x 6 bushes). The experiment assessed the effect of fertilization on yield, berry mass, fruit setting, leaf surface and physicochemical parameters of fruit. Based on the conducted research, it was proved that the applied fertilization technologies had a significant impact on the size and quality of the yield of "Bluecrop" highbush blueberry. Particularly noteworthy is the fertilization technology with biostimulation (treatment T4), which has a positive effect on the yield, fruit mass, percentage of setting and firmness of the berries. Analysis of the issue in the light of the results of the conducted research shows that the use of biostimulated products has an important impact on the intensification of production while maintaining good quality of fruits. Through research, the positive effect of fertilization programs with biostimulation (treatment T4) on the most important production parameters of blueberry fruit from the producer's point of view has been proven.

The Influence of Ultrasound and Cultivar Selection on the Biocompounds and Physicochemical Characteristics of Dried Blueberry (Vaccinium corymbosum L.) Snacks.

The aim of the study was to characterize physical and chemical composition of four highbush blueberry cultivars ("Bluecrop," "Late Blue," "Chandler," and "Elliot"). The assessment of ultrasound influence at the osmotic dehydration step and during hybrid drying on mass transfer and the nutritional quality of all cultivars was also done. The experiment consisted of two stages: (1) initial: optimization of osmotic dehydration procedure, (2) the main experiment including all stages of dried blueberry production (pretreatment, osmotic dehydration chosen in the initial stage, and drying). In both parts, the effect of US and cultivar were considered as factors influencing the most important quality indices. The osmotic dehydration, in the mixture (1:1) of sucrose solution and apple juice concentrate (65°Bx) at a fruit to syrup ratio 1:4, was carried out in water bath fitted with ultrasonic transducers (25 kHz, 27.8 W/L) at a temperature of 40°C for 150 min. After pretreatment osmo-dehydrated fruits were subjected to drying in hybrid (microwave-ultrasound-convective) drum dryer. Regardless of the cultivar US had positive influence on mass transfer (up to 22% for intact and 12% for mechanically scratched) at the osmotic dehydration stage. Unfavorably, its action tend to decrease phenolic compounds content. The final effect, however, was strongly influenced by the choice of cultivar. With regard to ultrasound applied at the drying step, no explicit effect, either on the drying process efficiency or on final product quality, was identified. In the same processing conditions "Elliot" turned out to be the most promising to produce ready-to-eat fruit snacks in terms of the final product stability and bioactives content. PRACTICAL APPLICATION: Hybrid drying was proposed as a novel approach in blueberry drying. Ultrasound application as a part of abovementioned drying technique is considered an efficient way of shortening drying time due to mass transfer intensification and the interaction with dehydrated tissue. However, no experiments studying the impact of ultrasound on various cultivars within one species were carried out. This study contributes to the understanding that appropriate cultivar selection in the production of ready-to-eat dried blueberry fruit is just as important as process parameters in obtaining an attractive product with a high level of natural bioactive compounds.

Clonal differences in antioxidant activity and bioactive constituents of hardy kiwifruit (Actinidia arguta) and its year-to-year variability.

BACKGROUND: Hardy kiwifruit (Actinidia arguta) is a new species, commercially grown in recent years. Total phenolics (TPC), vitamin C (TAA) content, antioxidant activity (AA) and their year-to-year variability in seven hardy kiwifruit clones were evaluated. TPC was determined using the Folin-Ciocalteu reagent assay. TAA was estimated by determination of l-ascorbic acid and l-dehydroascorbic acid levels using high-performance liquid chromatography. AA was measured using diphenyl-1-picryl-hydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and OH radicals. RESULTS: The highest content of vitamin C, in all seasons, was found in D11 (1447-2181 mg kg(-1) fresh weight) and phenolics for D11 and M1 clones (2583-3312 and 2228-3414 mg gallic acid equivalents kg(-1) fresh weight, respectively). TPC and TAA content showed significant differences between hardy kiwifruit clones and showed significant year-to-year variability. Each year, the level of AA was significantly higher for D11 (DPPH, ABTS). AA was strongly correlated with TPC and TAA content in Actinidia fruit. CONCLUSION: Hardy kiwifruit are an important source of vitamin C and phenolics, which resulted in their good antioxidant potential. A significantly higher content of these compounds was found in fruit of hybrid origin, which suggests that A. purpurea × A. arguta clones may be useful genetic resources for further interspecific hybridization.

Antioxidant activity and chemical difference in fruit of different Actinidia sp.

The present research aimed at evaluating the vitamin C, total phenolic content (TPC), phenolic compounds, carotenoids, and chlorophyll contents, as well as antioxidant activity (AAC) of six Actinidia species fruit. Vitamin C, phenolic compounds, carotenoids and chlorophylls were measured using high-performance liquid chromatography. TPC was determined using the Folin-Ciocalteau reagent, and AAC using 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay. The highest concentrations of vitamin C and TPC were found for Actinidia kolomikta fruit (1008.3 and 634.1 mg/100 g fresh weight [FW], respectively). Among phenolic compounds, seven phenolic acids and three flavonoids were identified. The 2,5-dihydroxybenzoic acid prevailed in A. kolomikta (425.54 mg/100 g FW), while tannic acid dominated in other species (4.63-100.43 mg/100 g FW). The largest amounts of chlorophylls and carotenoids were identified as Actinidia macrosperma (4.02 and 2.09 mg/100 g FW, respectively). The AAC of fruit extracts decreased in the order of A. kolomikta > Actinidia purpurea > Actinidia melanandra > A. macrosperma > Actinidia arguta > Actinidia deliciosa according to the DPPH assay.