The influence of irradiation of minimally processed cabbage and cucumber on microbial safety, texture, and sensory quality was investigated. Minimally processed, polyethylene-packed, and irradiated cabbage and cucumber were stored at refrigeration temperature (5 degrees C) for 2 weeks. The firmness values ranged from 3.23 kg (control) to 2.82 kg (3.0-kGy irradiated samples) for cucumbers, with a gradual decrease in firmness with increasing radiation dose (0 to 3 kGy). Cucumbers softened just after irradiation with a dose of 3.0 kGy and after 14 days storage, whereas the texture remained within acceptable limits up to a radiation dose of 2.5 kGy. The radiation treatment had no effect on the appearance scores of cabbage; however, scores decreased from 7.0 to 6.7 during storage. The appearance and flavor scores of cucumbers decreased with increasing radiation dose, and overall acceptability was better after radiation doses of 2.5 and 3.0 kGy. The aerobic plate counts per gram for cabbage increased from 3 to 5 log CFU (control), from 1.85 to 2.93 log CFU (2.5 kGy), and from a few colonies to 2.6 log CFU (3.0 kGy) after 14 days of storage at 5 degrees C. A similar trend was noted for cucumber samples. No coliform bacteria were detected at radiation doses greater than 2.0 kGy in either cabbage or cucumber samples. Total fungal counts per gram of sample were within acceptable limits for cucumbers irradiated at 3.0 kGy, and for cabbage no fungi were detected after 2.0-kGy irradiation. The D-values for Escherichia coli in cucumber and cabbage were 0.19 and 0.17 kGy, and those for Salmonella Paratyphi A were 0.25 and 0.29 kGy for cucumber and cabbage, respectively.

Pectin is a complex polysaccharide and natural food additive extracted from citrus peel and apple pomace in the form of brownish powder. It is widely used as a jelling and thickening agent and the food industry especially in jams and jellies. It is also recommended for use as fat replacer and also lowers blood cholesterol by increasing viscosity in the intestinal tract thus lowering cholesterol absorption. Peel of sweet oranges was chopped to small pieces in a vegetable cutter and dried in an electrical drier to 8-10% moisture contents. The dried peel was ground and then subjected to pectin extraction using water as solvent. Three treatments with different levels i.e., pH (1, 2, 2.5, 3, 3.5, 4, 4.5 and 5), temperature of solvent (70, 85 and 95°C) and extraction time (0.5, 1, 2, 3, 4 and 5 h) were evaluated. Development of an economical processing method for pectin extraction from citrus peel, that offers energetic properties nearly identical to those prepared by other methods (soxhlet method and microwave) using other substrates, is reported. Dried citrus peel contains about 30% pectin It has been found that 30 min heating at 70°C and pH level 2.5 resulted in 21% pectin extraction followed by 1 h heating at 85°C at pH level 3.0 and a similar pectin yield. Up to 17% yield was obtained for heating at 95°C at pH level 1 irrespective of the time of heating. It can be inferred from these experiments that pH range between 2.0-2.5 and heating at temperature of 70°C for 30 min seems to be the most suitable condition for pectin extraction as time and energy efficient process conditions.

Effect of gamma irradiation and washing on physicochemical and sensory quality of blood red oranges was investigated. The citrus fruits were packed in cellophane bags and stored at room temperature for 42 days. Two gamma irradiation doses 0.25 and 0.5 kGy alone and in combination with washing were applied to the fruits. Weight loss decreased with gamma irradiation and increased with washing during storage. Acidity and ascorbic acid values were higher for the oranges irradiated at 0.5 kGy and minimum for the washed oranges. Generally, total soluble solids (TSS) increased during the storage period. However, washed samples had the highest concentration and 0.5 kGy-irradiated samples had the lowest TSS at the end of the storage period. Sensory quality qualify by appearance, odour and taste are decreased during storage in both treatments. However, the fruits were still acceptable by the trained observers. It can be inferred from this study that irradiation at 0.5 kGy or in combination with washing is an effective post-harvest technique in keeping the changes in physicochemical and sensory quality to a minimum level during storage.Effects of gamma irradiation on quality of blood red oranges S. A. Khalil et al.

No abstract

Conventional methods for quantifying the added iron in wheat flour are time-consuming and costly. A rapid method (Time/Sample: 95 min) was developed by modifying the conventional standard method (Time/Sample: 560 min) and validated. Linearity and linear regression of the rapid method presented excellent correlation coefficient (R 2 ) values (0.9976 to 0.9991), which were close to 1, while the limits of agreement (LOA) were in the range of −0.01 to 0.06 mg/kg. The limits of detection (LOD)/specificity and limits of quantitation (LOQ)/ sensitivity values were found to be 0.03 and 0.09 mg/kg, respectively. The rapid method was subjected to validation, wherein the precision of intra-assay, inter-assay, and inter-person was determined to be within the range of 1.35−7.25%. These results indicate a high level of accuracy and precision of the method. The percent relative standard deviation (RSD) for recoveries at varying spiking levels, that is, 5, 10, and 15 mg/kg, was determined at 1.33 lying far below the upper limit of acceptability (RSD < 20). Overall, the developed rapid method can be sustainably alternate for conventional methods owing to its ability to produce accurate, precise, robust, and reproducible results.

No abstract