24 research outputs found
Assessment of antioxidant activity and total phenolic content from green coffee robusta sp. Beans
No full textMethanol and isopropanol were used as extraction solvent to determine the percentage yield of chlorogenic acid (CGA) in green Robusta (Coffea canephora) coffee bean. CGA was extracted by using isolation method with activated carbon to trap the CGA content from the complex compounds in green coffee beans. Results indicated that percentage yield of CGA extracted by using isopropanol was significantly higher (5.21%) compared to methanol (4.55%). Besides, antioxidant activity and total phenolic content were also analyzed. From this study, isopropanol extracted more antioxidant activity and total phenolic content as compared to methanol. For antioxidant activity, isopropanol and methanol extracted 0.48 mg and 0.15 mg of Fe (II) per gram of dry sample, respectively. For total phenolic content, isopropanol and methanol extracted 30.65 mg and 16.26 mg of gallic acid per gram of dry sample, respectively. Isopropanol extraction with ratio 60:40 (isopropanol: water) conserved more CGA content than methanol which was analyzed using high performance liquid chromatography. Chromatogram showed that the retention time of CGA is at 4.68 minutes which is similar to the retention time of standard CGA
Implications of inappropriate storage temperatures in harvested green coffee (robusta sp.) beans to antioxidant properties and polyphenol oxidase activity
No full textThe effects of various storage temperatures on antioxidant properties and
enzyme activity of green coffee beans were evaluated during storage. The
green coffee beans were harvested and stored at different storage
temperatures of 35 ?C, 26 ?C and 9 ?C. Lower storage temperature (9 ?C)
greatly preserved the reduction of phenolics and antioxidant capacity
detected using FRAP (Ferric Reducing Antioxidant Power) which was 38.20
mg TE/g, total phenolic content (TPC) which was 38.20 mg GAE/g and
DPPH (Radical Scavenging Effect) which was 82.56%. Temperature 9 ?C
also retained the moisture of the green coffee beans up to 54.31% at day 5.
For enzyme activity of polyphenol oxidase (PPO), the lower temperature
inactivated the enzyme which resulted in lower activity of the enzyme stored
at temperature 9 ?C which was 0.82 U/g followed by 0.90 U/g and 1.03 U/g
for 26 ?C and 35 ?C at day 1 of storage. However, green coffee beans stored
at 9 ?C showed some external chilling injury symptoms starting from day 7
of the storage. The phenolics and antioxidants activity in green coffee beans
during storage decreased with increase of storage temperature starting from
9 ?C, 26 ?C and 35 ?C. While the PPO activity increased with increase of
storage temperature
Feasibility of using combined Proton Transfer Reaction Mass Spectrometry (PTR-MS) technique and biochemical analyses to assess the quality of broccoli florets during postharvest storage, handling and temperature treatments
No full textThe objective of this research was to gain a better understanding of the relationship between changes in volatiles release, colour and biochemical markers (i.e. pigment content, antioxidant levels, activity of enzymes and oxidative damage levels) during postharvest storage and mechanical damage. This study attempted to find potential volatile markers, using Proton Transfer Reaction Mass Spectrometry (PTR-MS), that were statistically correlated with biochemical and physiological changes associated with postharvest storage and mechanical damage. Multivariate statistical analysis and regression analysis using Partial Least Squares Regression (PLSR) was used to evaluate possible correlations. It is hypothesized that volatile markers in combination with biochemical analyses can be used to assess quality changes during postharvest storage and handling of broccoli.
The intensity of protonated volatile organic compounds with the mass ions m/z 33 and m/z 49 were tentatively identified as methanol and methanethiol. While both increased, methanol was the dominant volatile detected. The increase of these mass ions was observed at the onset of senescence (Day 3, 23 °C), at which point chlorophyll breakdown was initiated, resulting in colour change from green to yellow. Validations were carried out using cytokinin 6-benzylaminopurine (BAP) which delays the onset of senescence for several days. Application of BAP delayed senescence in a concentration dependent manner, with 50 ppm or above BAP slowed the rate of senescence, as determined by chlorophyll loss measurement. Application of BAP also slowed the rate of methanol release. Colour change as a marker for the onset of senescence was validated using markers of oxidative damage and defence, which are known to be key indicators of the onset and progression of senescence. Depending on the BAP concentrations, measurements of antioxidant enzymes, non-enzymatic antioxidants and markers of oxidative damage confirmed that senescence was delayed. To further determine if the release of methanol was due to major cellular disruption, which occurs during senescence, broccoli florets at different stages of senescence were subjected to severe mechanical damage and the damaged tissues were monitored for up to six hours.
In addition, broccoli florets were subjected to different temperature treatments ranging from -18 to 100 °C to simulate different types of cellular and metabolic disruption. The stage of senescence prior to mechanical damage was the critical factor determining the cellular and metabolic integrity of broccoli samples six hours following the damage event although mechanical damage accelerated the breakdown of photosynthetic pigments, the inactivation of antioxidant enzymes, the degradation of non-enzymatic antioxidants and increases in the levels of oxidative damage and methanol.
The temperature treatments (-18, 50, 70 and 100 °C) disrupted cellular metabolism as evidenced by changes in the activities of several enzymes (POD, SOD, CAT and AAO) and led to significant increases in methanol release, compared to the control (4 °C). In addition, higher levels of methanethiol were detected from samples exposed to high temperatures.
Methanol (m/z 33) and methanethiol (m/z 49) are suggested to be potential volatile markers of broccoli florets that can be analysed using PTR-MS technique. Meanwhile, colour, pigment and ascorbic acid content are proposed as markers to determine the quality of broccoli
Feasibility of using combined Proton Transfer Reaction Mass Spectrometry (PTR-MS) technique and biochemical analyses to assess the quality of broccoli florets during postharvest storage, handling and temperature treatments
No full textThe objective of this research was to gain a better understanding of the relationship between changes in volatiles release, colour and biochemical markers (i.e. pigment content, antioxidant levels, activity of enzymes and oxidative damage levels) during postharvest storage and mechanical damage. This study attempted to find potential volatile markers, using Proton Transfer Reaction Mass Spectrometry (PTR-MS), that were statistically correlated with biochemical and physiological changes associated with postharvest storage and mechanical damage. Multivariate statistical analysis and regression analysis using Partial Least Squares Regression (PLSR) was used to evaluate possible correlations. It is hypothesized that volatile markers in combination with biochemical analyses can be used to assess quality changes during postharvest storage and handling of broccoli.
The intensity of protonated volatile organic compounds with the mass ions m/z 33 and m/z 49 were tentatively identified as methanol and methanethiol. While both increased, methanol was the dominant volatile detected. The increase of these mass ions was observed at the onset of senescence (Day 3, 23 °C), at which point chlorophyll breakdown was initiated, resulting in colour change from green to yellow. Validations were carried out using cytokinin 6-benzylaminopurine (BAP) which delays the onset of senescence for several days. Application of BAP delayed senescence in a concentration dependent manner, with 50 ppm or above BAP slowed the rate of senescence, as determined by chlorophyll loss measurement. Application of BAP also slowed the rate of methanol release. Colour change as a marker for the onset of senescence was validated using markers of oxidative damage and defence, which are known to be key indicators of the onset and progression of senescence. Depending on the BAP concentrations, measurements of antioxidant enzymes, non-enzymatic antioxidants and markers of oxidative damage confirmed that senescence was delayed. To further determine if the release of methanol was due to major cellular disruption, which occurs during senescence, broccoli florets at different stages of senescence were subjected to severe mechanical damage and the damaged tissues were monitored for up to six hours.
In addition, broccoli florets were subjected to different temperature treatments ranging from -18 to 100 °C to simulate different types of cellular and metabolic disruption. The stage of senescence prior to mechanical damage was the critical factor determining the cellular and metabolic integrity of broccoli samples six hours following the damage event although mechanical damage accelerated the breakdown of photosynthetic pigments, the inactivation of antioxidant enzymes, the degradation of non-enzymatic antioxidants and increases in the levels of oxidative damage and methanol.
The temperature treatments (-18, 50, 70 and 100 °C) disrupted cellular metabolism as evidenced by changes in the activities of several enzymes (POD, SOD, CAT and AAO) and led to significant increases in methanol release, compared to the control (4 °C). In addition, higher levels of methanethiol were detected from samples exposed to high temperatures.
Methanol (m/z 33) and methanethiol (m/z 49) are suggested to be potential volatile markers of broccoli florets that can be analysed using PTR-MS technique. Meanwhile, colour, pigment and ascorbic acid content are proposed as markers to determine the quality of broccoli
Systematic Review on Characterization of Tannase from Agricultural By-Products
Get PDFAbstractTannin-rich compounds are widely produced as by-products of many agro-industrial processes. Tannase is an attractive hydrolase for the bioconversion of tannin-rich materials into value-added products by accelerating the hydrolysis of ester and depside linkages. It has opened new opportunities in several industrial sectors, such as food, drinks, and medicines. Primary sources of tannase are microorganisms, particularly bacteria. Tannases or tannin acyl hydrolases, are an important group of biotechnologically relevant enzymes in several industrial applications. Microbial tannases are mostly induced extracellular enzymes produced by submerged and solid-state fermentation. Tannins containing low-value agro-industrial wastes are being extensively used in industries. This review provides a more in-depth knowledge of the research related to the biochemical characteristics of the tannase enzyme activity (in terms of molecular weight, the effect of pH, the effect of temperature, the effect of metal ions, inhibitor, and chelator), extraction, and purification methods. Additionally, the potential use of agricultural waste as a substrate for tannase production has also been reviewed, including the utilization of pomegranate peel waste (PmPW), banana peel waste (BPW), or potato peel waste (PtPW).Keywords: agricultural waste, tannase, tannin AbstrakSenyawa kaya tanin diproduksi secara luas sebagai produk sampingan dari banyak proses agroindustri. Tannase adalah hidrolase yang menarik untuk biokonversi bahan kaya tanin menjadi produk bernilai tambah dengan mempercepat hidrolisis ikatan ester dan depside. Hal tersebut telah membuka peluang baru di beberapa sektor industri, seperti makanan, minuman, obat-obatan, dan sebagainya. Sumber utama tannase adalah mikroorganisme, terutama bakteri. Tannase atau tanin asil hidrolase, adalah kelompok penting dari enzim yang relevan secara bioteknologi yang digunakan dalam beberapa aplikasi industri. Tannase dari mikroba sebagian besar diinduksi enzim ekstraseluler dan diproduksi oleh fermentasi terendam dan fermentasi keadaan padat. Tanin yang terkandung dalam limbah agroindustri bernilai rendah banyak digunakan dalam industri. Ulasan ini memberikan pengetahuan yang lebih mendalam tentang penelitian terkait karakteristik biokimia aktivitas enzim tannase (dari segi berat molekul, pengaruh pH, pengaruh suhu, pengaruh ion logam, inhibitor, dan chelator), metode ekstraksi dan pemurnian. Selain itu juga telah dikaji potensi pemanfaatan limbah pertanian sebagai prekursor ekstrak tannase, antara lain pemanfaatan limbah kulit buah delima (PmPW), limbah kulit pisang (BPW), atau limbah kulit kentang (PtPW).Kata Kunci: limbah pertanian, tannase, tanni
Table_1_Systematic Review on Food Safety and Supply Chain Risk Assessment Post Pandemic: Malaysian Perspective.DOCX
No full textThe novel coronavirus disease 2019, or COVID-19, is a recent disease that has struck the entire world. This review is conducted to study the impacts of the COVID-19 pandemic to food safety as well as the food supply chain. The pandemic has caused various changes around the world as numerous countries and governments have implemented lockdowns and restrictions to help curb the rising cases due to COVID-19. However, these restrictions have impacted many aspects of everyday life, including the economic sectors such as the food industry. An overview of the current COVID-19 situation in Malaysia was discussed in this review along with its implication on food safety and food supply chain. This is followed by a discussion on the definition of food safety, the impact of the pandemic to food safety, as well as the steps to be taken to ensure food safety. Hygiene of food handlers, complete vaccination requirement, kitchen sanitation and strict standard operating procedures (SOPs) should be in place to ensure the safety of food products, either in food industries or small scale business. Additionally, the aspect of the food supply chain was also discussed, including the definition of the food supply chain and the impact of COVID-19 to the food supply chain. Travel restriction and lack of manpower had impacted the usual operation and production activities. Lack of customers and financial difficulties to sustain business operational costs had even resulted in business closure. As a conclusion, this article provides insight into crucial factors that need to be considered to effectively contain COVID-19 cases and highlights the precaution methods to be taken through continuous monitoring and implementation by Malaysian government.</p
Occurrences of aflatoxins in selected rice production areas in Malaysia
No full textMycotoxins contamination in rice often occurs in the field prior to harvest, processing and storage. The possible coexistence of four mycotoxins in rice including aflatoxin B1, B2, G1 and G2 were investigatedin the present study. The samples of rice were collected in 33 rice production areas of Padiberas Nasional Berhad (BERNAS) Rice Factories (KBB) in Malaysia. These toxins were extracted from the samples, purified and finally quantified by high performance liquid chromatography (HPLC) with fluorimetry detection. Contamination of aflatoxin G1 was found to be the most prominent, followed by B2, G2 and B1. The coexistence of aflatoxin G1 in rice was found in the highest percentage. Occurrences of aflatoxin B1, B2, G1 and G2 at 36 rice production areas showed a significant difference between east, north and central Peninsular Malaysia ranging from 0.45 to 5.98 ng/g. The mean values for aflatoxin B1, B2, G1 and G2 were 3.234, 4.697, 6.588 and 0.773 ng/g, respectively. The total aflatoxin levels for Kuching (7.61 ng/g), KBB Sungai Limau (7.33 ng/g) and KBB Paya Keladi (6.59 ng/g) were found to exceed the levels set by the European Commission (EC) as well as by the Malaysia Food Regulation 1985. Moreover, the B1 levels for Kuching (3.56 ng/g) and Sarikei (2.42 ng/g) samples also exceeded the level set for B1 by the European Commission. Nevertheless, the findings showed that the concentrations of aflatoxin in most of the rice production areas in Malaysia are still below the permissible limit under both the EC and Malaysi
Data_Sheet_1_Systematic Review: Heat Treatments on Phenolic Content, Antioxidant Activity, and Sensory Quality of Malaysian Mushroom: Oyster (Pleurotus spp.) and Black Jelly (Auricularia spp.).docx
No full textPleurotus spp. and Auricularia spp. are popular species consumed by the Malaysian community. Recently, due to increased awareness, both mushrooms are also being consumed for their bioactive compounds, ergothioneine, and antioxidant properties and has been used since earlier ages as therapeutic remedies. The bioactive compounds such as phenol, flavonoid and ergothioneine found in both Pleurotus and Auricularia mushrooms were explored. Differences in heat treatments (microwave, hot air drying, and solar drying) and cooking methods may affect the content of bioactive compounds and their properties. Similarly, sensory acceptance by consumers may be affected too. Antioxidant properties using DPPH (1,1-diphenyl-2-picryl-hydrazyl) radical and FRAP (ferric reducing antioxidant power) assay of both raw and heat-treated mushrooms are included. Microwave drying retained color characteristics and bioactive compounds in both mushrooms. To add value to this review, a survey on the consumption pattern of Pleurotus and Auricularia species among Malaysians has been conducted online and concluded that Pleurotus species is the most considered species compared to Auricularia mushroom and almost half of the respondents were not aware that heat may deplete nutritional contents in mushroom despite agreeing both gave beneficial health in diets.</p
Nutritional, nutraceutical attributes, microbiological and chemical safety of different varieties of dates—A review
No full textDates are valued as a highly nutritious food with multiple nutraceutical properties. Date fruits are widely consumed, especially in the Middle Eastern regions. Dates are a vital source of readily metabolisable natural sugars, minerals, vitamins, dietary fibre, protein, and other high-value natural antioxidant compounds such as carotenoids and phenolics. Nutritional and nutraceutical composition and properties of dates vary according to variety, origin, fruit maturity level, and post-harvest processing conditions. Dates, like many other fruits, are susceptible to microbial contamination, particularly during improper pre- and post-harvest handling and storage. The prevalence of mycotoxin and bacterial contamination not only spoils the functional food quality of dates nevertheless it poses potential adverse effects on human health. With increased interest in the health benefits of dates, there is a greater need to examine and understand potential microbiological safety issues linked with commercial dates. The main goal of this review is to present comprehensive and most up-to-date scientific findings about the high-value components profile, nutritional and nutraceutical qualities, and microbiological safety of various types of dates consumed around the world. Furthermore, the study urges innovative mitigation strategies to combat microbial contamination while maintaining the safety and quality of dates supplied and consumed as part of the food chain
Exploring the functional properties and nutritional values of colored oyster mushrooms species (Pleurotus, Agaricomycetes): a review
No full textColored oyster mushrooms species of genus Pleurotus are a variety of edible mushrooms that attract a lot of interest among the consumers and scientists due to its scientific evidence that they have promising health benefits. However, information on their characteristics and properties is still scarce. Consequently, it is important to determine the potential health benefits of the mushrooms. This review paper presents an overview of functional properties and nutritional values of colored oyster mushrooms (Pleurotus spp.). It particularly discusses the types of pigments present in Pleurotus spp., their characteristics, and potential nutritional values. Pigments such as melanin, carotenoids, and flavonoids are reported to be present in colored oyster mushrooms. Moreover, the antioxidant compounds of these mushrooms have been unveiled, demonstrating their potential to counteract oxidative stress and improve general health. In addition, the investigation into the nutritional characteristics of the mushrooms reveals encouraging aspects for their incorporation into dietary considerations. Thus, it can be concluded that colored Pleurotus species have an immense amount of potential for use as natural colorants, as well as nutritious and antioxidant-rich compounds. These mushrooms represent an important advancement in the search for functional foods due to their significant nutrients such as proteins, amino acids, carbohydrates, and fibers
