Freezing characteristics and texture variation after freezing and thawing of four fruit types

One major problem with frozen fruits is a loss of texture. Therefore this study investigated the effects of the freezingprocess on the freezing profiles, texture, and drip loss of apple, mango, cantaloupe, and pineapple fruit samples. All frozenthawedfruits varied in these three properties because of diversity in the fresh fruits. Mango had the highest total solublesolids content and the lowest freezing point, whereas pineapple showed the highest freezing rate. The highest firmness andcrunchy texture were found in fresh apple, and these properties were absent in the other fresh fruits. The firmness of allfrozen fruits significantly decreased by different percentages as compared to those of the fresh fruits. The drip loss of eachfruit type was also significantly different with apple samples having the highest firmness decrease and drip loss. This studyshows that freezing characteristics and frozen fruit properties depend on type of fruit

Texture improvement of fresh and frozen mangoes with pectin methylesterase and calcium infusion

Abstract BACKGROUND: A major problem of mango products is texture loss. The effect of commercial pectin methylesterase (PME) and calcium infusion on improvement of the texture of both fresh and frozen-thawed mango cubes was investigated in the present study

The combined effect of calcium, pectin methylesterase and mild heat on frozen mango quality

Both single and mixed solutions of calcium and pectin methylesterase were studied to examine how they improve the quality of frozen mango. The result showed that calcium and pectin methylesterase had a synergistic effect on the mango, helping to improve firmness and decrease the drip loss of the frozen fruit. To increase the efficiency of the mixed solution of pectin methylesterase and calcium, this study examined three immersion temperatures (25, 40 and 50 °C). Pectin methylesterase activity, calcium content, -carotene content, firmness, drip loss and color of the samples were evaluated. The treatment at 40 °C caused high pectin methylesterase activity and calcium content. The firmness of the frozen-thawed mango increased two-fold from 1.25 to 2.50 N, and the drip loss decreased from 15.19 to 9.87 g/100 g when compared with the control samples. Moreover, the frozen-thawed mango that was immersed in pectin methylesterase and calcium at 40 °C had the highest lightness and hue value and the lowest browning index

Antibiotic Resistance of Lactic Acid Bacteria Isolated from Cambodian Fish Paste Product

Fish paste product is considered an important food in Cambodia. However, the status of antimicrobial susceptibility of microbes in this product are a concern. This study aimed to isolate lactic acid bacteria (LAB) from Cambodian fish paste and to investigate their resistant property of antibiotics. Fifteen LABs were isolated with cell forms of 14 as cocci and 1 as rods. Isolates of the bacteria were identified as Staphylococcus piscifermentans (14 strains) and Lactobacillus plantarum (1 strain). Using the disk diffusion method, the resistance was investigated of the 15 LAB isolate strains to eight clinically crucial antibiotics: penicillin (Pen), ampicillin (Amp), erythromycin (Ery), tetracycline (Tet), vancomycin (Van), streptomycin (Str), sulfamethoxazoletrimethoprim (Sul) and metronidazole (Met). It was found that all 15 LAB isolates were resistant to Met. One isolate strain was resistant to Pen, Amp, Tet, Str and Sul. Furthermore, 7 and 2 isolate strains were resistant to Tet and Van, respectively. All 15 isolate strains were sensitive to Str and Ery. The LAB isolate strains were sensitive to Pen, Amp, Sul (14 strains), Tet (6 strains) and Van (13 strains). These results showed that 14 of the LAB isolate strains were sensitive to 5 antibiotics (Pen, Amp, Ery, Str and Sul) and could be considered as strains for utilization as starter culture for fish fermentation. Additionally, these finding will be conduct to assess the antibiotic resistance incidences of LABs in Cambodian fermented foods

Effect of pectin methyl esterase (PME) and CaCl2 infusion on the cell integrity of fresh-cut and frozen-thawed mangoes: An NMR relaxometry study

This study describes the use of Nuclear Magnetic Resonance (NMR) relaxometry to understand the effect of pectin methyl esterase (PME) + CaCl2 infusion under different conditions on cell integrity of fresh-cut and frozen-thawed mangoes. Infusion experiments were performed at: atmospheric pressure, vacuum conditions of 50 kPa and 10 kPa. For NMR relaxometry experiments T-2 (spin-spin relaxation time), T-1 (spin-lattice-relaxation times) and 2D T-1-T-2 experiments were performed. Results showed that, as the severity of the vacuum treatment increased, the relaxation times changed significantly (p < 0.05). The number of compartments observed in 1-D relaxation spectra of fresh and frozen-thawed mangoes changed with different treatments. The changes in relaxation times were explained due to formation of a gel formed by the interaction of pectin and calcium. 2D T-1-T-2 relaxation maps showed that compartmentalization was retained after vacuum treatment even for frozen-thawed samples. The study showed that NMR relaxometry is a useful tool to analyze the cell integrity of mangoes exposed to different treatments