Phenolic and antioxidant capacity retention of potato peel waste as a function of cultivar, pretreatment and drying procedure

Drying procedures employed for potato peels (both raw and boiled) may adversely affect the useful bioactivecomponents present in them. This study envisaged the identification of a feasible drying procedure for handlingbulk potato peel waste for maximising the retention of phytochemicals in the peel powder. The total phenols (TP), flavonoids (TF) and antioxidant capacity (TAC) were assessed in peels of three commercial and one newly developed anthocyanin rich Indian potato cultivars in response to boiling pretreatment and varying drying procedures. Microwave drying (600W) was best in terms of drying rate for both raw and boiled peels. It yielded the greatest amount of TP and TF in the dried raw peel, irrespective of cultivar. Dried raw peels of an thocyanin rich Kufri Neelkanth cultivar exhibited maximum TAC. Retention of TF, metal scavenging activity and reducing power followed almost a similar pattern as TP irrespective of cultivar, pretreatment and drying procedure. Our study shows that potato peel from Kufri Neelkanth (raw) and Kufri Frysona (both raw and boiled) are best source of phenolics and flavonoids and can serve as a suitable matrix for extraction of bioactive compounds which holds promise for use in the food industry

Potential of X-ray imaging to detect citrus granulation in different cultivars with progress in harvesting time

263-268Granulation, a physiological disorder of citrus is manifested by shriveled juice sacs and internal dryness. Extractable juice in granulated tissue is drastically reduced as a consequence of gelatinization and secondary epidermis formation. Since, the defect cannot be detected externally it leads to consumer dissatisfaction and poor returns to farmers. Processing industry also faces huge economic loss due to reduction in the juice recovery from granulated fruit. In this context, here, we studied the possibility of developing an image processing algorithm through MATLAB software to detect granulation with advancement of maturity via X-ray micrographs. Fruit of eight citrus cultivars comprising of granulation susceptible and tolerant varieties harvested at four different intervals were exposed to X-rays. Voltage of 46 kV and current of 6.5 mA given to fruit for an exposure time of 320 mAs gave the best X-ray image contrasts. The developed algorithm could effectively distinguish the healthy and granulated fruit with an accuracy of 90% as validated by subsequent destructive analysis when estimated for four different harvesting dates. The imaging technique can be employed by the processors to determine the severity of granulation and to sort out fruit online which will help in saving economic losses

Microfluidization of juice extracted from partially granulated citrus fruits: Effect on physical attributes, functional quality and enzymatic activity

Citrus juice sac granulation reduces the yield of extractable juice and impairs its nutritional and functional quality. Therefore, present study was carried out to improve the physico-functional quality of juice extracted from partially granulated ‘Dancy’ tangerine. Juice was passed through microfluidizer under varying pressure (41, 62, 83, 103, 124 MPa) for different number of passes (1, 2, 3). The microfluidized juice was evaluated for different quality attributes, viz. cloud value, fractal dimension, lacunarity, colour attributes and pectin methyl esterase (PME) activity. Naringin and hesperidin were quantified through HPLC. Control juice exhibited the highest fractal dimension (18.89), indicating irregular cell structure, while 103MPa/3 passes (1.04) displayed the lowest indicating uniformity in juice. Microfluidized juice showed improved opalescence stability, greater hue, low PME activity and augmented hesperidin and naringin contents. Juice treated at 103 MPa for a single pass exhibited the best organoleptic quality. The high pressure applied during microfluidization can drastically improve the quality of otherwise low quality juice extracted from granulated citrus fruits. Application of appropriate processing pressure and number of passes through the microfluidizer yields citrus juice possessing enhanced bioactive constituents, reduced enzymatic activity with good organoleptic acceptability

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Not AvailableThe present study was conducted to assess the variations in quality characteristic of nine commonly cultivated citrus genotypes grown in semi-arid region. Fruit weight varied from 130g (‘Minneola’) to 622g (‘Pummelo Red Flesh’) within different groups of citrus fruits. Juice content ranged from 31% (‘Pummelo Red Flesh’) to 54% (‘Mosambi’). Pummelo fruits were larger in size than fruits of other citrus groups. TSS varied from 8°B (‘Dancy’) to 11°B (‘Pummelo Red Flesh’), while ascorbic acid varied from 32 to 54 mg/100g. The maximum phenolic content was recorded in ‘Pummelo White Flesh’ fruits (44.66 mg GAE/100g) and the minimum was found in ‘Minneola’ (23.33 mg GAE/100g). The fruits of ‘Pummelo Red Flesh’ and ‘Pummelo White Flesh’ had highest flavonoids of 50.85 mg QE/100g and 48.10 mg QE/100g, respectively. The antioxidant activity was also high in the fruits of pummelo and grapefruit as compared to others. Principal Component Analysis revealed that TSS and acid content were the major quality attributes governing the citrus acceptability. Total flavonoid content and the in vitro FRAP antioxidant assay were the best to determine the functional quality of the fruits. Biplot analysis grouped the genotypes into two groups and the result was further verified by Agglomerative Hierarchical Clustering technique which too yielded similar results.Not Availabl

Potential of X-ray imaging to detect citrus granulation in different cultivars with progress in harvesting time

Granulation, a physiological disorder of citrus is manifested by shriveled juice sacs and internal dryness. Extractable juice in granulated tissue is drastically reduced as a consequence of gelatinization and secondary epidermis formation. Since, the defect cannot be detected externally it leads to consumer dissatisfaction and poor returns to farmers. Processing industry also faces huge economic loss due to reduction in the juice recovery from granulated fruit. In this context, here, we studied the possibility of developing an image processing algorithm through MATLAB software to detect granulation with advancement of maturity via X-ray micrographs. Fruit of eight citrus cultivars comprising of granulation susceptible and tolerant varieties harvested at four different intervals were exposed to X-rays. Voltage of 46 kV and current of 6.5 mA given to fruit for an exposure time of 320 mAs gave the best X-ray image contrasts. The developed algorithm could effectively distinguish the healthy and granulated fruit with an accuracy of 90% as validated by subsequent destructive analysis when estimated for four different harvesting dates. The imaging technique can be employed by the processors to determine the severity of granulation and to sort out fruit online which will help in saving economic losses