pH and Titratable Acidity

Author(s):  
George D. Sadler ◽  
Patricia A. Murphy
Keyword(s):  
Author(s):  
María Lorena Luna-Guevara ◽  
Teresita González-Sánchez ◽  
Adriana Delgado-Alvarado ◽  
María Elena Ramos-Cassellis ◽  
José Guillermo Pérez-Luna ◽  
...  

Objective: To study the effect of storage temperatures and dehydration conditions (solar and convective drying; SD, CD), on the quality, physicochemical parameters and antioxidant properties of tomato fruits. Methodology: The physicochemical characteristics pH, titratable acidity, soluble solids (°Bx) and color parameters (L*, a* and b*), were evaluated. The lycopene, carotenoids and antioxidant activity percentages retention of tomatoes fruits stored at 7 and 22 ° C for 5 days and subjected to SD (Temperature (T) of 67 °C and luminescence of 685 lum/sqf) and CD (T 70 °C, flow rates 0.5, 1.0 and 1.5 m/s), were analyzed. Results: The fruits reached humidities of 17 and 15% for SD and CD. The parameters pH, °Bx, L*, a*, b* were highest with 22°C and CD (1.5 m/s). The value of the carotenoids was higher in fruits stored at 7 ° C and subjected to CD (1.0 and 1.5 m/s) and SD with values of 83.85, 85.98 and 99.43%, respectively. The CD (0.5 m/s) and SD improved lycopene (94.37 and 95.14%) and the antioxidant activity with values of 73.06 and 97.21%. Implications: The application of solar dehydration depends on luminescence condition; however, it is inexpensive and environmentally friendly alternative. Conclusions: The results derived in a viable alternative for the conservation and commercialization of tomato fruits in rural communities


Author(s):  
A. Vovkohon ◽  
V. Nadtochiy ◽  
G. Kalinina ◽  
O. Hrebelnyk ◽  
N. Fedoruk ◽  
...  

The article highlights comparative research results of milk quality indices obtained from the milking in specialized milking halls with such milking units as «Parallel», «Carousel» or in stalls with the milking unit «Molokoprovid». The fat and protein mass fraction, dry matter and fat-free dry matter, density, titratable and active acidity, heat resistance and freezing point have been determined according to the accepted techniques. The electrical conductivity of milk has been determined by using the analytical device MD-20 MAS-D-TEC. The total amount of milk bacteria has been determined by reductase reduction test and by seeding method in Petri dish. The milk quality has been investigated by the fermentation and rennet fermentation tests. The higher indices of the fat mass fraction, the protein mass fraction and the dry substance concentration of milk, obtained in specialized milking halls, have been established. This is not statistically significant. Milk, obtained from the milking unit «Molokoprovid», has higher index of titratable acidity, lower thermal stability in comparison with milk, obtained from specialized milking halls with milking units «Parallel» and «Carousel». It has been determined that there is the bacteria insemination increase in milk received from milking cows in stalls in comparison with milk, obtained from milking in specialized halls. Milk, obtained from the milking unit «Carousel», indicates the subclinical form of mastitis in cows or «Carousel» operation violationif there is in 1,8 mS/cm conductivity increase above average index 4,6 mS/cm. Key words: technology, quality and safety of milk, milking, milking unit, milking hall, bacterial insemination.


2020 ◽  
Vol 3 (1) ◽  
pp. 47
Author(s):  
Nadezhda Petkova ◽  
Manol Ognyanov ◽  
Blaga Inyutin ◽  
Petar Zhelev ◽  
Panteley Denev

Crab apple (Malus baccata (L.) Borkh.) was mainly distributed in Europe as an ornamental plant, but the nutritional properties of its edible fruits were not fully revealed. The aim of the current study was to characterize the phytochemical composition of ripen carb apple fruits and to evaluate their nutritional and antioxidant potentials. The fruits were assayed for moisture and ash content, proteins, lipids, carbohydrates, titratable acidity (TA), pH, total phenolic compounds and natural pigments. Among the analyzed carbohydrates cellulose was found in the highest content (6% dw), followed by sugars (sucrose, glucose and fructose) and 1.8 % dw uronic acids. The total chlorophylls and carotenoids contents in their fruits were 6.51 and 4.80 μg/g fw, respectively. Total monomeric anthocyanins were not detected. The highest content of total phenolic compounds (2.67 mg GAE/g fw) was found in 95 % ethanol extract from fruits, while the total flavonoids were relatively low – 0.1 mg QE/g fw. DPPH assay (17.27 mM TE/g fw) and FRAP assay (14.34 mM TE/g fw) demonstrated in vitro antioxidant activities of crabapple. Malus baccata fruits were evaluated as a rich source of dietary fibers and phenolic compounds with significant antioxidant potential that could be used in human nutrition.


2019 ◽  
Vol 14 (7) ◽  
pp. 649-657 ◽  
Author(s):  
Li Li ◽  
Jiemin Li ◽  
Jian Sun ◽  
Ping Yi ◽  
Changbao Li ◽  
...  

Background: Phospholipase D (PLD)is closely related to browning and senescence of postharvest longan fruit. Objective: This study investigated the effects of 2-butanol (a PLD inhibitor) on the expression and regulation of PLD during storage of longan fruit at a low temperature. Methods: Senescence-related quality indices showed that the 2-butanol-treated fruit presented lower pericarp browning index, pulp breakdown index and total soluble solid value than the untreated fruit. Results: The fruit treated by 60 µL/L 2-butanol exhibited the strongest inhibition on senescence, which significantly delayed changes in weight, titratable acidity content, total soluble solid content and ascorbic acid content. This treatment maintained a high level of total phenolic content and caused significant inhibition on pericarp browning and pulp breakdown. Through ELISA method, 60 µL/L 2-butanol treatment also reduced PLD activity. Real-time RT-PCR (RT-qPCR) results showed that PLD mRNA expression level was inhibited by 60 µL/L 2-butanol within 15 days. Western-blotting results further confirmed the differential expression of PLD during storage, and a relatively higher expression for PLD protein was found in control compared to the 2-butanoltreated fruit during 15-d storage. Conclusion: These results provided a scientific basis and reference to further investigating postharvest longan quality maintenance by regulating the PLD gene expression.


2017 ◽  
Vol 39 (1) ◽  
pp. 103 ◽  
Author(s):  
Luciana Ercoli ◽  
Érica Oliveira Barizão ◽  
Joana Shuelter Boeing ◽  
Marcus Vinícius Kvitschal ◽  
Jesuí Vergilio Visentainer ◽  
...  

In this research, the total phenolic content (TPC) and antioxidant capacity (FRAP and DPPH•× assays) of pulps and peels of advanced selection of apples grown in Brazil were investigated. The correlation analyses between the activity of polyphenoloxidase enzyme (PPO), vitamin C content, total titratable acidity, and color parameters were performed. The results indicated that the data differed significantly among the apple genotypes studied. The peels of the selection Epagri 170-91 and Epagri 170-25 showed the highest TPC and antioxidant capacities. In addition, the pulps of the Epagri 170-91 presented the highest TPC and antioxidant capacities, the lowest enzymatic browning, highest amount of vitamin C and lowest enzymatic activity when compared with other genotypes. The TPC and antioxidant capacities were significantly correlated in all genotypes analyzed. High correlation values between enzymatic browning and factors that affect the apple color were also found in all analyzed pulps, except between enzymatic browning and TPC. The results demonstrated that the enzymatic browning and TPC, as well as the antioxidant capacity and chemical characteristics, vary considerably depending on the apple genotypes and fruit tissues analyzed. 


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