Screening of the alterations in qualitative characteristics of grape under the impacts of storage and harvest times using artificial neural network

Bagging Strategy and Identification of Coloring Mode of ‘Xinqihong’ Pear

‘Xinqihong’ is a recently selected and well-colored red pear (Pyrus bretschneideri Rehd.) cultivar that is popular in the marketplace owing to the bright red color and high quality of the fruit. The red pigmentation is strongly associated with the light signal. However, its responses to bagging treatment and to light exposure after shading are unknown. In this study, the fruit were treated with three types of fruit bags. ’Xinqihong’ fruit colored rapidly in response to light stimulation. A white fruit bag was optimal for bagging of ‘Xinqihong’ fruit. To ensure satisfactory red pigmentation, the fruit required exposure to 30 days of light after bag removal. A transcriptome analysis was conducted to screen light-signal-related genes and identify their possible functions. PbCRY1 activated the promoter of PbHY5.2 and enhanced its expression. PbHY5.2 activated the promoter activity of PbUFGT and induced anthocyanin synthesis, and also showed self-activation characteristics. Both PbCRY2 and PbPHY1 induced anthocyanin accumulation. Thus, blue-light receptors played an important role in anthocyanin synthesis. This study provides a theoretical basis for the bagging cultivation of new varieties of ‘Xinqihong’, and lays a foundation for the study of the mechanisms of red pear fruit coloring in response to light signals.

Nutraceutical and Functional Properties of Peel, Pulp, and Seed Extracts of Six ‘Köhnü’ Grape Clones

Grape production has a long history in the Elazig province and surrounding vicinity and produced grapes have been used for table consumption and also processed into traditional beverages, Şıra (special non-alcoholic grape juice) and wine. In the Elazig province, the main grape cultivars are ‘Ağın Beyazı’, ‘Öküzgözü’, ‘Boğazkere’, ‘Şilfoni’, ‘Tahannebi’, and ‘Köhnü’. Among them, ‘Köhnü’ cultivar is highly preferred by consumers due to its black color and perfect berry characteristics. The cultivar has grown for centuries in different parts of Elazig and shows a great variability for most of its morphological and biochemical characteristics. In the present study, we aimed to determine morphological and biochemical traits in six ‘Köhnü’ clones sampled from Elazığ. The cluster weight of six clones was found between 334–394 g. The highest total phenolic content was observed in seeds followed by peel and pulp samples. The seed extract of Clone 2 had the highest total phenolic content at 254 mg gallic acid equivalent/100 g fresh weight. The results also showed that peel, pulp, and seed samples of ‘Köhnü’ grape clones had considerable amounts of antioxidant components determined by DPPH (1,1-Diphenyl-2-picryl-hydrazyl), FRAP (ferric reducing antioxidant power), and TEAC assays and might be rich sources of natural antioxidants. Among the six ‘Köhnü’ clones, Clone 3, and Clone 6 differed from the others in respect to the highest cluster weight, the highest concentrations of total phenolic content, and antioxidant activity. The results also implied that all clones could be used potentially as a readily accessible source of natural antioxidants and as a possible pharmaceutical supplement.

Influence of Long-Term Storage on the Caking Properties Determined in Punch Test and Fungal Contamination of Potato Starch and Wheat Flour

The presented results are an attempt to identify the changes taking place during a punch test experiment and the development of fungal impurities of powdered food materials over long-term storage at 75% RH. The potato starch and wheat flour market has a large share of the global production of bulk materials. The growing interest in powdered food materials requires additional production expenditure. This is associated with an increase in storage time of the discussed product and providing it with the appropriate conditions. The samples of potato starch and wheat flour were stored in perforated containers in a climatic chamber at 75% humidity and 21 °C for five months and then samples were measured by a punch test in a Lloyd LRX materials testing machine. The graphs obtained in the potato starch punch test differed significantly from wheat flour. The thickening of potato starch was observed in the form of layers, while potato starch was uniformly thickened throughout the experiment. The conditions of 75% humidity and 21 °C can be described as the beginning of the caking process. In potato starch, linear sections were observed, which changed the length of their storage time and, additionally, was correlated with the appearance of fungal contamination. These results may suggest the influence of fungi on the phenomenon of bulk material caking.

Modeling of Linear and Non-linear Compression Processes of Sunflower Bulk Oilseeds

The present study aimed at describing the experimental and theoretical force-deformation curves of sunflower bulk oilseeds at varying initial pressing heights and vessel diameters as well as determining the theoretical pressure and energy along the screw press FL 200 pressing chambers. The design of efficient oil expression systems for industry and small-scale application remains a major challenge to engineers and researchers. In attempting to solve the problem, it is important to understand the linear compression process and to transfer the knowledge to the industry involving mechanical screw presses. The universal compression testing machine at a preset load of 200 kN and a speed of 5 mm·min−1, tangent curve model and the screw press FL 200 geometry parameters were applied. The obtained results of pressure and energy along the screw pressing chambers (1–7) ranged from 0.31 to 101.653 MPa and 12.616 to 1231.228 J. Applying the tangent model at n = 1 and n = 2, the cumulative pressure decreased with increasing vessel diameters while energy increased. The study provides useful information for the analysis of other bulk oilseeds and optimizing the processing parameters of screw press FL 200 and the design and development of new oil presses.

Microwave Pretreatment and Enzymolysis Optimization of the Lotus Seed Protein

Pretreatment with a microwave was conducted before enzymolysis and shown to enhance the enzymolysis, which changed the secondary structure of the lotus seed protein. Under high-power microwave irradiation, sub bonds of the protein were broken, causing disaggregation and unfolding of the secondary structure, namely a decrease in the intermolecular aggregate structure and increase in the random coil structure, making the protein bonds susceptible to papain in the enzymolysis. On the other hand, a response surface methodology (RSM) was launched to investigate the influence of the enzymolysis process variables on the DH (degree of hydrolysis). The statistical analysis revealed that the optimized conditions were a protein substrate concentration of 15 g/L, pH of 5.5, enzymolysis temperature of 57 °C, papain amount of 0.5 g/L, and enzymolysis time of 45 min, for which the predicted value of the DH was 35.64%. The results indicated that a microwave also had better potential for applications in the enzymolysis of foods.