This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The present study investigated the interaction effects (additive, synergistic, and antagonistic) ... more The present study investigated the interaction effects (additive, synergistic, and antagonistic) of different groups of spices, their constituent phenolic compounds, and synthetic antioxidants on the total phenol (TP) content and antioxidant activity, as measured by the ferric-reducing antioxidant power (FRAP) of the mixtures. The results showed that there was an additive effect in all the groups studied, except for the group containing turmeric or curcumin. The groups containing turmeric or curcumin showed a moderate synergistic effect. Among the groups of spices, the highest summated TP (50.6 mg GAE/mL) and FRAP (106.2 mg Trolox/mL) values were observed in the group containing clove, cinnamon, pimento, rosemary, oregano, and cardamom. In the case of the groups of pure phenolics, the highest summated TP (364.96 mg GAE/mL) and FRAP (1124.25 mg Trolox/mL) values were observed in the group containing eugenol, acetyl eugenol, caffeic acid, and protocatechuic acid. The summated and comb...
The aim of this study was to examine the applicability of delactosed whey permeate (DWP) treatmen... more The aim of this study was to examine the applicability of delactosed whey permeate (DWP) treatment on preserving the quality and antioxidant attributes of fresh-cut tomato. Tomatoes were treated with 3 % DWP by dipping, spraying and a combination of both, stored at 4 °C for 10 days and compared with the industrial standard, chlorine. The combination of dipping and spraying of DWP showed the best results for all the markers tested. The combined treatment of dipping and spraying of DWP significantly lowered total counts (~ 1.0 log cfu/g), yeast and moulds (~ 1.2 log cfu/g), inhibited the loss of firmness (25 %) and reduced POD activity (15 %) of the tomato slices after 10 days compared to the chlorine treatment. Moreover, DWP treated tomatoes maintained significantly (p<0.05) higher levels of vitamin C, total phenols (TP) and antioxidant activity (DPPH) than the chlorine treated samples during storage. Sensory scores confirmed that DWP treated tomatoes retained better aroma and texture. Also, the appearance and overall acceptability were higher than chlorine treated tomatoes. Thus DWP treatment has potential to extend the shelf-life of fresh-cut tomatoes.
The objective of this study was to investigate the efficacy of delactosed whey permeate (DWP) tre... more The objective of this study was to investigate the efficacy of delactosed whey permeate (DWP) treatment on the physico-chemical, microbial and antioxidant compounds of tomatoes stored at 15 °C for 21 days compared with traditional chlorine treatment. Fresh tomatoes were treated with 3 ml/100ml DWP or 120 mg/L chlorine solutions and packed in perforated polypropylene bags. The results showed that DWP treatment significantly reduced the number of total aerobic counts (~1.62 log cfu/g) and yeast and moulds (~1.66 log cfu/g) of tomatoes compared to chlorine during storage. Moreover, the tomatoes treated by DWP remained firmer (22 %) than the control fruits and maintained significantly (p<0.05) higher levels of vitamin C (15 %), total phenols (10 %) and antioxidant activity (26 %) at the end of storage. Sensory scores confirmed that the DWP treated tomato fruits retained a good appearance and overall quality compared to the chlorine treated samples. The aroma and texture attributes were maintained better in DWP treated tomatoes than chlorine treated tomatoes during storage. Therefore, DWP treatment could be used as a potential washing agent for fresh tomatoes to extend the shelf-life and maintain the nutritional quality during storage.
Optimization of delactosed whey permeate (DWP) treatment for fresh-cut tomato was accomplished by... more Optimization of delactosed whey permeate (DWP) treatment for fresh-cut tomato was accomplished by evaluating different quality, nutritional and microbial markers. Response surface methodology was applied to obtain polynomial model equations. DWP concentration (0-5 %) and storage (0-10 days) were used as independent factors in order to optimize the process. The analyses showed that increases in DWP concentration extended the quality of the fresh-cut tomato significantly (p<0.05) by maintaining texture, antioxidant activity (FRAP) and controlling the spoilage during the storage. However, concentrations >3 % were scored unacceptable by the sensory panel due to perceived offodours. DWP treatment also improved retention of ascorbic acid and lycopene over storage. The total aerobic counts and yeast and moulds were reduced by ~1.5 log cfu/ g and ~1.0 log cfu/ g respectively after 10 days of storage treated with 3 % DWP. Predicted models were highly significant (p<0.05) for all the markers studied in fresh-cut tomato with high regression coefficients (R 2) ranging from 0.79 to 0.99. The study recommends the use of DWP at a concentration of 3 % to extend the shelf-life of fresh-cut tomato by preserving its quality and antioxidant properties during storage.
International Journal of Food Science & Technology, 2012
The aim of this study was to investigate the effect of delactosed whey permeate (DWP) treatment o... more The aim of this study was to investigate the effect of delactosed whey permeate (DWP) treatment on antioxidant and physico-chemical properties of strawberries. Fresh strawberries 28 treated with 3 % DWP were analyzed for different quality, nutritional and microbiological 29 markers during 10 days of storage at 5 °C. The results showed that DWP treatment 30 significantly reduced incidences of decay (70 %) and numbers of total aerobic counts (~1.4 31 Log 10 CFU/g) and yeast and moulds (~1.8 Log 10 CFU/g). DWP treatment also inhibited the loss of firmness (15 %) and maintained significantly (p<0.05p≤0.05) higher levels of vitamin C, total phenols and antioxidant activity of strawberries. Sensory scores confirmed that the DWP treated strawberries retained a good appearance and overall quality. The aroma and 35 colour attributes were not reduced during storage. These results suggest that DWP treatment has potential to extend the shelf-life and maintain the quality of strawberries during storage.
The aim of this research was to analyse the effects of three types of cheese whey permeate treatm... more The aim of this research was to analyse the effects of three types of cheese whey permeate treatment on the antioxidant properties of fresh-cut tomatoes. Tomatoes were treated with whey permeate concentrate (PC), delactosed permeate (DP) and delactosed concentrate (DC), stored at 4°C for 10 days and compared to the samples treated with industrial standard, chlorine (120 ppm). Samples were analysed for ascorbic acid, lycopene, total phenols, mineral and trace elements and antioxidant activity (DPPH and FRAP). The samples treated with DP retained significantly (p<0.05) higher antioxidant activity (FRAP) and total phenols (TP) when compared with those treated with PC and DC respectively. DP showed significantly (p<0.05) higher results than chlorine for DPPH, FRAP and TP. In DPPH assay, all whey permeate-treated samples showed similar antioxidant activity. No significant differences in levels were found among whey permeates and chlorine treatments for naturally present antioxidants such as ascorbic acid and lycopene. The statistical analysis showed a positive significant (R 2 =0.9173, p<0.05) correlation between TP and the antioxidant activity. A good correlation was observed between DPPH and FRAP assay (R 2 =0.8005, p<0.05). Among the three whey permeates, delactosed permeate showed the best results in maintaining the antioxidant properties of tomato. These results suggest that whey permeate could be used to enhance the antioxidant activity of the fresh-cut tomato while retaining the antioxidant components during storage.
The effect of delactosed whey permeate (DWP) treatment on antioxidant and phyto-chemical componen... more The effect of delactosed whey permeate (DWP) treatment on antioxidant and phyto-chemical components of canned Irish plum tomatoes were investigated. Tomatoes were sterilized for 5 min (F 0) at 120 °C and stored for 6 months. The DWP treatment retained significantly (p<0.05) higher levels of ascorbic acid and lycopene of tomatoes. The antioxidant activity of DWP treated tomatoes was higher (7 %) than the control at the end of storage. The firmness in DWP-treated fruits was around 40 % higher than that in control. All the parameters decreased significantly (p<0.05) during storage except lycopene and total phenols. Lycopene content showed no significant change and total phenols increased during storage. The changes in ascorbic acid, antioxidant activity and texture were fitted well to Weibull kinetic models with high coefficients of determination (R 2) and low RMSEC (root mean sum of squared error). The results clearly indicate that DWP enhanced the retention of antioxidant compounds in tomatoes during storage.
The effects of three whey permeates were investigated as potential natural washing treatment for ... more The effects of three whey permeates were investigated as potential natural washing treatment for fresh-cut tomato and compared with chlorine (120 ppm). Whey permeate treated samples resulted in equivalent or better than chlorine for all these attributes. Whey permeates were equally effective as chlorine to control the microorganisms of fresh-cut tomato during storage. The microbial counts at day 10 were significantly reduced (~1.0 log CFU/g) in all the treated samples compared to the control (water treated) samples. Moreover whey permeate treated freshcut tomatoes showed lower water activity (2 %) and POD activities (21%) than chlorinated samples after 10 days of storage. Whey permeate also inhibited the loss of firmness of treated tomato slices. Sensory scores for aroma were significantly higher in whey permeate treated samples than chlorine treated samples. Among the three types of whey permeate, delactosed permeate (DP) showed the best results in maintaining the quality of fresh-cut tomato. PRACTICAL APPLICATIONS The market sales of ready-to-eat fresh vegetables have grown rapidly in recent decades as a result of changes in consumer attitudes. The marketing of fresh-cut vegetables is limited by their short shelf-life due to the quick decline in post-processing quality. Many attempts have been made to increase the shelf life of fresh-cut fruit and vegetables and many attempts have been made to increase the use of whey permeate, a valuable by-product of cheese processing industry. This paper takes an interesting approach by attempting to use whey permeate as a preserving agent of fresh-cut tomato quality during storage.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The present study investigated the interaction effects (additive, synergistic, and antagonistic) ... more The present study investigated the interaction effects (additive, synergistic, and antagonistic) of different groups of spices, their constituent phenolic compounds, and synthetic antioxidants on the total phenol (TP) content and antioxidant activity, as measured by the ferric-reducing antioxidant power (FRAP) of the mixtures. The results showed that there was an additive effect in all the groups studied, except for the group containing turmeric or curcumin. The groups containing turmeric or curcumin showed a moderate synergistic effect. Among the groups of spices, the highest summated TP (50.6 mg GAE/mL) and FRAP (106.2 mg Trolox/mL) values were observed in the group containing clove, cinnamon, pimento, rosemary, oregano, and cardamom. In the case of the groups of pure phenolics, the highest summated TP (364.96 mg GAE/mL) and FRAP (1124.25 mg Trolox/mL) values were observed in the group containing eugenol, acetyl eugenol, caffeic acid, and protocatechuic acid. The summated and comb...
The aim of this study was to examine the applicability of delactosed whey permeate (DWP) treatmen... more The aim of this study was to examine the applicability of delactosed whey permeate (DWP) treatment on preserving the quality and antioxidant attributes of fresh-cut tomato. Tomatoes were treated with 3 % DWP by dipping, spraying and a combination of both, stored at 4 °C for 10 days and compared with the industrial standard, chlorine. The combination of dipping and spraying of DWP showed the best results for all the markers tested. The combined treatment of dipping and spraying of DWP significantly lowered total counts (~ 1.0 log cfu/g), yeast and moulds (~ 1.2 log cfu/g), inhibited the loss of firmness (25 %) and reduced POD activity (15 %) of the tomato slices after 10 days compared to the chlorine treatment. Moreover, DWP treated tomatoes maintained significantly (p<0.05) higher levels of vitamin C, total phenols (TP) and antioxidant activity (DPPH) than the chlorine treated samples during storage. Sensory scores confirmed that DWP treated tomatoes retained better aroma and texture. Also, the appearance and overall acceptability were higher than chlorine treated tomatoes. Thus DWP treatment has potential to extend the shelf-life of fresh-cut tomatoes.
The objective of this study was to investigate the efficacy of delactosed whey permeate (DWP) tre... more The objective of this study was to investigate the efficacy of delactosed whey permeate (DWP) treatment on the physico-chemical, microbial and antioxidant compounds of tomatoes stored at 15 °C for 21 days compared with traditional chlorine treatment. Fresh tomatoes were treated with 3 ml/100ml DWP or 120 mg/L chlorine solutions and packed in perforated polypropylene bags. The results showed that DWP treatment significantly reduced the number of total aerobic counts (~1.62 log cfu/g) and yeast and moulds (~1.66 log cfu/g) of tomatoes compared to chlorine during storage. Moreover, the tomatoes treated by DWP remained firmer (22 %) than the control fruits and maintained significantly (p<0.05) higher levels of vitamin C (15 %), total phenols (10 %) and antioxidant activity (26 %) at the end of storage. Sensory scores confirmed that the DWP treated tomato fruits retained a good appearance and overall quality compared to the chlorine treated samples. The aroma and texture attributes were maintained better in DWP treated tomatoes than chlorine treated tomatoes during storage. Therefore, DWP treatment could be used as a potential washing agent for fresh tomatoes to extend the shelf-life and maintain the nutritional quality during storage.
Optimization of delactosed whey permeate (DWP) treatment for fresh-cut tomato was accomplished by... more Optimization of delactosed whey permeate (DWP) treatment for fresh-cut tomato was accomplished by evaluating different quality, nutritional and microbial markers. Response surface methodology was applied to obtain polynomial model equations. DWP concentration (0-5 %) and storage (0-10 days) were used as independent factors in order to optimize the process. The analyses showed that increases in DWP concentration extended the quality of the fresh-cut tomato significantly (p<0.05) by maintaining texture, antioxidant activity (FRAP) and controlling the spoilage during the storage. However, concentrations >3 % were scored unacceptable by the sensory panel due to perceived offodours. DWP treatment also improved retention of ascorbic acid and lycopene over storage. The total aerobic counts and yeast and moulds were reduced by ~1.5 log cfu/ g and ~1.0 log cfu/ g respectively after 10 days of storage treated with 3 % DWP. Predicted models were highly significant (p<0.05) for all the markers studied in fresh-cut tomato with high regression coefficients (R 2) ranging from 0.79 to 0.99. The study recommends the use of DWP at a concentration of 3 % to extend the shelf-life of fresh-cut tomato by preserving its quality and antioxidant properties during storage.
International Journal of Food Science & Technology, 2012
The aim of this study was to investigate the effect of delactosed whey permeate (DWP) treatment o... more The aim of this study was to investigate the effect of delactosed whey permeate (DWP) treatment on antioxidant and physico-chemical properties of strawberries. Fresh strawberries 28 treated with 3 % DWP were analyzed for different quality, nutritional and microbiological 29 markers during 10 days of storage at 5 °C. The results showed that DWP treatment 30 significantly reduced incidences of decay (70 %) and numbers of total aerobic counts (~1.4 31 Log 10 CFU/g) and yeast and moulds (~1.8 Log 10 CFU/g). DWP treatment also inhibited the loss of firmness (15 %) and maintained significantly (p<0.05p≤0.05) higher levels of vitamin C, total phenols and antioxidant activity of strawberries. Sensory scores confirmed that the DWP treated strawberries retained a good appearance and overall quality. The aroma and 35 colour attributes were not reduced during storage. These results suggest that DWP treatment has potential to extend the shelf-life and maintain the quality of strawberries during storage.
The aim of this research was to analyse the effects of three types of cheese whey permeate treatm... more The aim of this research was to analyse the effects of three types of cheese whey permeate treatment on the antioxidant properties of fresh-cut tomatoes. Tomatoes were treated with whey permeate concentrate (PC), delactosed permeate (DP) and delactosed concentrate (DC), stored at 4°C for 10 days and compared to the samples treated with industrial standard, chlorine (120 ppm). Samples were analysed for ascorbic acid, lycopene, total phenols, mineral and trace elements and antioxidant activity (DPPH and FRAP). The samples treated with DP retained significantly (p<0.05) higher antioxidant activity (FRAP) and total phenols (TP) when compared with those treated with PC and DC respectively. DP showed significantly (p<0.05) higher results than chlorine for DPPH, FRAP and TP. In DPPH assay, all whey permeate-treated samples showed similar antioxidant activity. No significant differences in levels were found among whey permeates and chlorine treatments for naturally present antioxidants such as ascorbic acid and lycopene. The statistical analysis showed a positive significant (R 2 =0.9173, p<0.05) correlation between TP and the antioxidant activity. A good correlation was observed between DPPH and FRAP assay (R 2 =0.8005, p<0.05). Among the three whey permeates, delactosed permeate showed the best results in maintaining the antioxidant properties of tomato. These results suggest that whey permeate could be used to enhance the antioxidant activity of the fresh-cut tomato while retaining the antioxidant components during storage.
The effect of delactosed whey permeate (DWP) treatment on antioxidant and phyto-chemical componen... more The effect of delactosed whey permeate (DWP) treatment on antioxidant and phyto-chemical components of canned Irish plum tomatoes were investigated. Tomatoes were sterilized for 5 min (F 0) at 120 °C and stored for 6 months. The DWP treatment retained significantly (p<0.05) higher levels of ascorbic acid and lycopene of tomatoes. The antioxidant activity of DWP treated tomatoes was higher (7 %) than the control at the end of storage. The firmness in DWP-treated fruits was around 40 % higher than that in control. All the parameters decreased significantly (p<0.05) during storage except lycopene and total phenols. Lycopene content showed no significant change and total phenols increased during storage. The changes in ascorbic acid, antioxidant activity and texture were fitted well to Weibull kinetic models with high coefficients of determination (R 2) and low RMSEC (root mean sum of squared error). The results clearly indicate that DWP enhanced the retention of antioxidant compounds in tomatoes during storage.
The effects of three whey permeates were investigated as potential natural washing treatment for ... more The effects of three whey permeates were investigated as potential natural washing treatment for fresh-cut tomato and compared with chlorine (120 ppm). Whey permeate treated samples resulted in equivalent or better than chlorine for all these attributes. Whey permeates were equally effective as chlorine to control the microorganisms of fresh-cut tomato during storage. The microbial counts at day 10 were significantly reduced (~1.0 log CFU/g) in all the treated samples compared to the control (water treated) samples. Moreover whey permeate treated freshcut tomatoes showed lower water activity (2 %) and POD activities (21%) than chlorinated samples after 10 days of storage. Whey permeate also inhibited the loss of firmness of treated tomato slices. Sensory scores for aroma were significantly higher in whey permeate treated samples than chlorine treated samples. Among the three types of whey permeate, delactosed permeate (DP) showed the best results in maintaining the quality of fresh-cut tomato. PRACTICAL APPLICATIONS The market sales of ready-to-eat fresh vegetables have grown rapidly in recent decades as a result of changes in consumer attitudes. The marketing of fresh-cut vegetables is limited by their short shelf-life due to the quick decline in post-processing quality. Many attempts have been made to increase the shelf life of fresh-cut fruit and vegetables and many attempts have been made to increase the use of whey permeate, a valuable by-product of cheese processing industry. This paper takes an interesting approach by attempting to use whey permeate as a preserving agent of fresh-cut tomato quality during storage.
Uploads
Papers by Lubna Ahmed