The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform

Muhammad Junaid - One of the best experts on this subject based on the ideXlab platform.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations. Methods Raw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT Treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes. Results Compositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT Treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C_18:1 and C_18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C_18:1 and C_18:2 in UHT Treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C_18:1 and C_18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT Treatment and storage period significantly affected the concentration of organic acids in milk. After UHT Treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO_2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT Treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT Treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days. Conclusion The results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk.
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Ali Imran, Muhammad Junaid
    Abstract:

    Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations. Raw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT Treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes. Compositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT Treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C18:1 and C18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C18:1 and C18:2 in UHT Treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C18:1 and C18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT Treatment and storage period significantly affected the concentration of organic acids in milk. After UHT Treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT Treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT Treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days. The results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.

Muhammad Ajmal - One of the best experts on this subject based on the ideXlab platform.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations. Methods Raw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT Treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes. Results Compositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT Treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C_18:1 and C_18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C_18:1 and C_18:2 in UHT Treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C_18:1 and C_18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT Treatment and storage period significantly affected the concentration of organic acids in milk. After UHT Treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO_2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT Treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT Treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days. Conclusion The results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk.
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Ali Imran, Muhammad Junaid
    Abstract:

    Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations. Raw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT Treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes. Compositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT Treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C18:1 and C18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C18:1 and C18:2 in UHT Treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C18:1 and C18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT Treatment and storage period significantly affected the concentration of organic acids in milk. After UHT Treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT Treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT Treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days. The results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.

Muhammad Nadeem - One of the best experts on this subject based on the ideXlab platform.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations. Methods Raw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT Treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes. Results Compositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT Treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C_18:1 and C_18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C_18:1 and C_18:2 in UHT Treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C_18:1 and C_18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT Treatment and storage period significantly affected the concentration of organic acids in milk. After UHT Treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO_2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT Treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT Treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days. Conclusion The results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk.
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Ali Imran, Muhammad Junaid
    Abstract:

    Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations. Raw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT Treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes. Compositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT Treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C18:1 and C18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C18:1 and C18:2 in UHT Treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C18:1 and C18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT Treatment and storage period significantly affected the concentration of organic acids in milk. After UHT Treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT Treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT Treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days. The results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.

Paz M De Pena - One of the best experts on this subject based on the ideXlab platform.

  • effect of ultra high temperature UHT Treatment on coffee brew stability
    Food Research International, 2013
    Co-Authors: Patricia Sopelana, Monica Perezmartinez, Isabel Lopezgalilea, Paz M De Pena
    Abstract:

    Abstract In this work, the influence of an Ultra High Temperature (UHT) Treatment on chemical and sensory composition of Arabica coffee brews for a longer shelf-life has been studied. A temperature of 120 °C for 2 s allows to obtain a microbiologically safe coffee brew, good valued from the sensory point of view. The behavior of the UHT vs non UHT treated coffee brew was followed throughout 120 days of storage at 4 °C. The UHT Treatment keeps the typical acidity of the brews longer, delaying and softening the pH decrease and the development of sourness, which is one of the main causes for the rejection of stored coffee brews. The UHT Treatment hardly affects the concentrations of caffeine and trigonelline, and of some phenolic compounds such as 5-caffeoylquinic (5-CQA), caffeic or ferulic acids. Sixteen key odorants and staling volatiles were analyzed by HS–GC–MS and lower changes were observed in the UHT treated coffee brew throughout storage. Higher DPPH scavenging activity was observed in the UHT treated coffee brew from days 60 to 120. In conclusion, the application of an UHT Treatment is proposed to extend the shelf-life (up to 60 days) of stored coffee brews.

Muhammad Imran - One of the best experts on this subject based on the ideXlab platform.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk.
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations.

  • Lipid compositional changes and oxidation status of ultra-high temperature treated Milk
    Lipids in Health and Disease, 2018
    Co-Authors: Muhammad Ajmal, Muhammad Nadeem, Muhammad Imran, Muhammad Junaid
    Abstract:

    Background Milk fat is one of the complex fat and most sensitive biochemical compounds towards auto-oxidation. To enhance the shelf life, milk is subjected to Ultra-high Temperature (UHT) Treatment followed by aseptic packaging. During the storage, several chemical and biochemical changes take place in lipid fraction of UHT milk. In current investigation, the effect of UHT Treatment and storage was determined by making a comparison in fatty acid profile, triglyceride composition, organic acids and lipid oxidation of the thermally treated and stored milk with raw milk, which was not reported in earlier investigations. Methods Raw milk samples were collected from the bulk storage facility of a dairy industry. The same milk was routed to UHT Treatment and aseptically packaged samples were collected. The fatty acid profile, triglyceride composition, organic acids and lipid oxidation was determined in raw and UHT treated milk at 0, 30, 60 and 90 days. Fatty acid and triglyceride profile was determined on GC-MS while organic acids were determined by HPLC. For the measurement of induction period, professional Rancimat was used. Lipid oxidation was characterized through free fatty acids, peroxide value, anisidine value and conjugated dienes. Results Compositional attributes of milk remain unchanged during the entire length of storage. Concentrations of short-chain fatty acids in raw and UHT milk were 10.49% and 9.62%. UHT Treatment resulted in 8.3% loss of short-chain fatty acids. Up to 30 days, storage did not have any significant effect on fatty acid profile of UHT milk. Concentration of medium-chain fatty acids in raw and UHT treated milk was 54.98% and 51.87%. After 30, 60 and 90 days of storage, concentration of medium chain fatty acids was found 51.23%, 47.23% and 42.82%, respectively. Concentration of C_18:1 and C_18:2 in raw and UHT milk was 26.86% and 25.43%, respectively. The loss of C_18:1 and C_18:2 in UHT Treatment was 5.32%. After 30, 60 and 90 days of storage, the concentrations of C_18:1 and C_18:2 were 24.6%, 21.06% and 18.66%, respectively. Storage period of 30 days was found non-significant, while noticeable variations were found in triglyceride profile of 60 and 90 days old samples of UHT milk. UHT Treatment and storage period significantly affected the concentration of organic acids in milk. After UHT Treatment, concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid increased by 3.45, 0.66, 3.57, 0.68, 2.24, 2.16 and 1.63 mg/100 g. Effect of storage period on the production of organic acids in UHT milk was non-significant up to 30 days. After 60 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 3.79, 0.75, 4.69, 0.78, 2.83, 3.03 and 2.38 mg/100 g. After 90 days of storage period, the increase in concentration of lactic acid, acetic acid, citric acid, pyruvic acid, formic acid, succinic acid and oxalic acid was 7.3, 2.18, 9.96, 3.58, 11.37, 5.22 and 5.96%. Free fatty acids content of raw, UHT treated and 90 days old milk were 0.08%, 0.11% and 0.19%. UHT treated version of milk showed similar peroxide value. While, the storage remarkably affected the peroxide value. After 30, 60 and 90 days, peroxide value was 0.42, 0.62 and 1.18 (MeqO_2/kg). Induction period of raw, UHT and stored milk was strongly correlated with peroxide value and fatty acid profile. Mean value of lipase activity in raw milk was 0.73 ± 0.06 μmoles/ml. UHT Treatment significantly decreased the lipase activity. The lipase activity of milk immediately after the UHT Treatment was 0.18 ± 0.02 μmoles/ml. Lipase activity of UHT milk after 30, 60 and 90 days of room temperature storage was 0.44 ± 0.03, 0.95 ± 0.07 and 1.14 ± 0.09 μmoles/ml. Color, flavor and smell score decreased through the storage of UHT milk for 90 days. Conclusion The results of this investigation revealed that fatty acid and triglyceride profile changed after 60 and 90 days of storage. Production of organic acids led to the drop of pH and sensory characteristics in UHT milk during the long-term storage. Induction period can be successfully used for the determination of anticipatory shelf life of UHT milk.