Pencirian bakteria asid laktik dan sebatian aroma ikan pekasam

Dalam kajian ini, bakteria asid laktik (LAB) serta sebatian aroma ikan pekasam daripada spesies yang berbeza ditentukan. Persampelan ikan pekasam iaitu tilapia, loma, lampam, sepat dan gelama diperoleh daripada pembekal Perusahaan Ikan Pekasam Kiah di Kuala Kangsar, Perak. Penentuan spesies LAB dijalankan melalui kaedah pencairan bersiri, pengkulturan LAB, ujian katalase, ujian pewarnaan spora serta ujian pengesanan Gram bakteria dan morfologi. Pengesahan spesies LAB dijalankan melalui pengekstrakan asid deoksiribonukleik (DNA), amplifikasi dengan tindak balas rantaian polimerasi (PCR), analisis elektroforesis gel dan penjujukan DNA. Hasil jujukan DNA yang diperoleh dibandingkan dengan jujukan dalam pangkalan data GenBank di NCBI menggunakan BLAST. Didapati Lactobacillus brevis KB290 DNA dan Lactobacillus casei W56 wujud dalam pekasam tilapia, Lactobacillus plantarum 16 dalam pekasam lampam, Lactobacillus casei BD-II kromosom dan Lactobacillus plantarum WCFS1 dalam pekasam sepat, Corynebacterium vitaeruminis DSM 20294 dan Streptococcus anginosus C1051 dalam pekasam gelama. Manakala Staphylococcus carnosus subsp. carnosus TM300 kromosom adalah LAB dominan dalam pekasam loma. Sementara itu, sebatian aroma ditentukan melalui kaedah pengekstrakan cecair menggunakan pelarut metanol dan heksana. Pemprofilan sebatian aroma dijalankan dengan kromatografi gas-spektometer jisim (GC-MS). Sebatian aroma dalam ekstrak metanol dan heksana daripada lima jenis ikan pekasam dibandingkan. Bilangan sebatian aroma yang diekstrak menggunakan metanol adalah lebih banyak berbanding dengan yang menggunakan heksana. Sebatian aroma yang paling banyak dikesan adalah daripada pekasam loma. Asid karboksilik merupakan sebatian yang paling dominan dalam ikan pekasam dan memberi bau hamis serta tengik

Seaweed tea: fucoidan-rich functional food product development from Malaysian brown seaweed, Sargassum binderi

Our previous studies on fucoidan from Malaysian brown seaweed, Sargassum binderi, found that it exhibited significant secondary anti-oxidative activity and showed non-toxicity. In order to exploit its health benefits, fucoidan-rich seaweed tea was developed in this study. A total of 4 different brewing time treatments were performed on Sargassum binderi at 5, 10, 15 and 20 mins (Ft05, Ft10, Ft15 and Ft20, respectively). It was found that Ft20 showed significantly (p<0.05) highest fucoidan content (27.22 ± 0.07 mg/200 mL), superoxide anion scavenging activity (16.46 ± 2.83%) and hydroxyl radical scavenging activity (89.83 ± 4.11%) compared to that of Ft05, Ft10 and Ft15. Both the secondary antioxidant activities were significantly positive correlated to the fucoidan content tests (superoxide anion scavenging activity at r=0.97, p=0.0052; and hydroxyl radical scavenging activity at r=0.99, p=0.0011). Masking of the seaweed odour was performed using lemon essence and discriminative test found that masking was most effective using lemon essence at a concentration of 0.3% (v/v). Therefore, there is potential for this seaweed tea to be commercialised, thus, consumers may acquire the health benefit of fucoidan

Kesan kaedah pemendakan berbeza terhadap ciri fizikokimia dan aktiviti antioksidan alginat daripada Sargassum sp.

Alginat merupakan polisakarida berstruktur anionik yang terdapat dalam matriks alga perang dan lazimnya digunakan sebagai agen penggelan, pengemulsi dan penstabil dalam industri makanan. Objektif utama kajian dijalankan adalah untuk mengenal pasti kesan kaedah pemendakan berbeza terhadap ciri fizikokimia alginat. Dalam kajian ini, alginat telah diekstrak daripada Sargassum sp. dengan menggunakan dua kaedah pemendakan yang berbeza iaitu melalui pemendakan dengan garam kalsium dan asid (sampel A) dan juga pemendakan dengan asid dan etanol (sampel B). Analisis ATR-FTIR telah mengesahkan kehadiran alginat dalam kedua-dua ekstrak Sargassum sp. Hasil pengekstrakan alginat bagi sampel A dan sampel B masing-masing adalah 28.16% dan 18.24%. Ciri fizikokimia yang diuji ialah warna, kelikatan, aktiviti penggelan dan kuasa pemerangkapan radikal bebas DPPH dan dibandingkan dengan alginat komersial (Sigma-Aldrich). Alginat yang terhasil adalah berwarna kuning kecoklatan dan mempunyai kelikatan pseudoplastik dengan penipisan ricih. Aktiviti penggelan kedua-dua sampel (A & B) adalah berbeza secara signifikan, (p<0.05) dengan alginat komersial. Kuasa pemerangkapan radikal bebas DPPH sampel A adalah lebih tinggi berbanding alginat komersial (20.10 ±3.84 & 11.89 ±3.12). Secara keseluruhan, kaedah pemendakan sampel A adalah lebih baik berbanding sampel B disebabkan oleh hasil alginat yang tinggi, aktiviti antioksidan yang tinggi dan ciri fizikokimia yang hampir setanding dengan alginat komersial

Effects of fermentation time and pH on soursop (Annona muricata) vinegar production towards its chemical compositions

Vinegar is a liquid product that undergoes both alcoholic and acetous fermentation of sugar (carbohydrate) sources. Soursop (Annona muricata) is easily available in Malaysia throughout the year. However, it is also highly perishable and has a short shelf-life. Therefore, in this research, soursop was used in the production of vinegar, to increase its utilisation and reduce wastage. The objectives of this research were to determine the effects of fermentation time and pH on soursop vinegar using a 3 × 5 factorial design and to determine its chemical compositions. It was found that pH and fermentation time showed significant (p0.05). It was evident that the sugar concentration reduces over time and it was inversely proportional to the ethanol and acetic acid concentrations, due to the conversion of sugar to ethanol and subsequently acetic acid. It was found that higher pH (pH5.5) gave significantly (p0.05) effect on ethanol production. There were no significant differences (p>0.05) in vitamin C content in all vinegar samples. Thus, it can be established that at fermentation time of 120 h and pH5.5, more sugar was used and more ethanol and acetic acid were produced

Comparison of amino acids profile and antioxidant activities between edible bird nest and chicken egg

Edible bird’s nest (EBN) and eggs are sources of high quality protein. The objectives of this study were to compare the amino acid profile between EBN and eggs to determine the differences in nutrition composition and antioxidant properties. Amino acid profile and antioxidant properties (DPPH, ABTS and FRAP) of four samples, raw EBN (EBNraw), EBN hydrolysates (EBNh), commercial chicken egg (Eggcomm) and free range chicken egg (EggFR) were determined and correlated with one another. It was found that EBN raw and EBNh have significantly higher (p<0.05) DPPH and ABTS activities compared to Eggcomm and EggFR, whereas Eggcomm and EggFR have significantly higher (p<0.05) FRAP activities compared to EBNraw and EBNh. Amino acid profile analysis showed that Eggcomm and EggFR have significantly higher (p<0.05) methionine, cysteine, lysine and isoleucine content compared to EBNraw and EBNh. Histidine, proline, phenylalanine and tryptophan in EBN were found to have significant (p<0.01) positive correlation with DPPH and ABTS antioxidant activities assays, while methionine and cysteine in chicken eggs have significant (p<0.01) positive correlation with FRAP activity. In conclusion, both EBN and chicken eggs are good sources of proteins and essential amino acids, but EBN showed higher antioxidant activities

Effect of different hydrolysis time and enzymes on chemical properties, antioxidant and antihyperglycemic activities of edible bird nest hydrolysate

Edible bird nest (EBN) is a dried glutinous secretion from the salivary glands of swiftlet species commonly found in the Southeast Asian region, including Malaysia. It is consumed traditionally by the Chinese as food delicacy and also considered as an important ingredient in traditional Chinese medicine for its beneficial health effects. The aim of this study was to evaluate the effect of enzymatic hydrolysis using alcalase, papain and papaya juice hydrolyze at 0.5 to 3 hr on the degree of hydrolysis (DH), protein solubility, concentration of reducing sugar, antioxidant and anti-hyperglycemic activity. In general, an increase in hydrolysis time increases the DH and soluble protein digestion rate. However, the concentration of reducing sugar was not affected by hydrolysis time. The solubility of proteins was highest for alcalase and papain at 3 h, while papaya juice at 2 h. Papain showed the highest antioxidant activity in 1 and 2 h of hydrolysis time whereas at 3 h, results for both papain and alcalase were higher compared to papaya juice. Result of anti-hyperglycemic activity showed that only EBN hydrolyzed using papaya juice has positive activity. Based on this study, enzymatic hydrolysis had improved the functional properties of EBN and results showed the potential of EBN to be developed as natural antioxidants and anti-hyperglycemic agents

Kesan kaedah pengeringan dan pelarut yang berbeza terhadap kandungan fenol, aktiviti antioksidan dan antihiperglisemik ekstrak rizom halia hutan (Alpinia mutica Roxb.)

Alpinia mutica Roxb. (Zingiberaceae), juga dikenali sebagai halia hutan ialah sejenis tumbuhan yang kaya dengan sumber bahan bioaktif, berupaya menentang sel kanser dan berpotensi untuk bertindak sebagai agen antioksidan. Kajian ini dijalankan untuk mengkaji kesan kaedah pengeringan (pengeringan ketuhar (PK) dan sejuk beku (PB)) serta penggunaan campuran pelarut etanol dan air pada nisbah yang berbeza (100:0, 50:50 dan 0:100) terhadap kandungan fenol, aktiviti antioksidan dan antihiperglisemik ekstrak rizom A. mutica (ERA). Kandungan fenol ERA dikaji dengan ujian penentuan Jumlah Kandungan Fenol (TPC) manakala aktiviti antioksidan ditentukan dengan Ujian Aktiviti Penyingkiran Radikal Bebas (DPPH) dan Ujian Kuasa Penurunan Ferik (FRAP). Aktiviti antihiperglisemik dikaji melalui perencatan enzim α-glukosidase. Hasil kajian ini menunjukkan bahawa penggunaan kaedah pengeringan dan pelarut yang berbeza mempengaruhi kandungan fenol, aktiviti antioksidan dan kesan antihiperglisemik ERA. Sampel PK yang diekstrak dengan nisbah pelarut 100:0 menunjukkan aktiviti antioksidan (DPPH) dan kesan antihiperglisemik yang terbaik dengan nilai kepekatan perencatan separuh maksimum (IC50) yang paling rendah, 550.94 ± 50.02 dan 84.97 ± 11.69 μg/mL. Sampel PK (100:0) juga mencatatkan kandungan fenol (155.55 ± 9.36 mg GAE/g ekstrak) dan nilai FRAP (108.98 ± 10.08 mg TEAC/g ekstrak) yang tertinggi dengan perbezaan yang ketara berbanding dengan sampel lain (p < 0.05). Korelasi positif antara TPC dengan aktiviti antioksidan dan antihiperglisemik menunjukkan kebarangkalian bahawa sebatian fenol ialah komponen yang bertanggungjawab terhadap aktiviti biologi yang diperoleh. Hasil kajian ini menunjukkan bahawa teknik pengeringan dan nisbah pelarut ekstrak yang digunakan jelas mempengaruhi kandungan fenol, aktiviti antioksidan dan kesan antihiperglisemik (ERA)

Characterization of edible swiftlets nest as a prebiotic ingredient using a simulated colon model

Purpose: Edible bird’s nest (EBN) has been considered as one of the nutritious foods and was also claimed to aid in digestion problems. Potential prebiotic of the EBN for gut health by the presence of glycan within the complex structure of the EBN glycoprotein to date has not been reported. The gut health can contribute to the overall consumers’ health in the improvement of the gut beneficial bacterial growth. In this study, the potential prebiotic of the EBN was conducted using a simulation of in vitro human colon model system. Methods: The EBN-extracted glycan and EBN glycoprotein (crude sample) were digested using in vitro oral, gastric and duodenal model system. Prebiotic activities of the undigested EBN glycan and EBN glycopeptide compounds were studied with the fructooligosaccharide as a positive control, using inoculum of 10% (w/v) faecal bacteria in the in vitro fermentation system. Result: The fermentation of EBN glycan and EBN glycopeptide had shown significant increases of the gut beneficial bacteria and was comparable with fructooligosaccharide fermentation, with each sample presented different profiles of bacterial growth. The fermentation of EBN glycan and EBN glycopeptide demonstrated an increase in the total short-chain fatty acid production, particularly acetate, propionate and butyrate. Conclusion: These findings suggested that the EBN can be functioned as a natural prebiotic upon consumption, thus providing a potential as prebiotic ingredients

Chemical changes and optimisation of acetous fermentation time and mother of vinegar concentration in the production of vinegar-like fermented papaya beverage

Fermentation has been long used as a method to produce beverage of various health benefits. In this research, ripe papaya (Carica papaya) was fermented through alcoholic fermentation using Saccharomyces cerevisiae, followed by acetous fermentation using Acetobacter spp. from mother of vinegar, to reduce wastage of this highly perishable Malaysian fruit. The papaya juice was pasteurised prior to the fermentation process. Optimisation of acetous fermentation was carried out using the response surface methodology (RSM) with central composite rotatable design (CCRD). Acetous fermentation time had shown significant effect on all the chemical characteristics while mother of vinegar concentration did not significantly effect on all the chemical characteristics. The vinegar-like fermented papaya beverage which was produced at the optimum point (Fermentation time = 70.80 h and concentration = 40% mother of vinegar) contained 0.37 ± 0.01% reducing sugar, 3.54 ± 0.36% ethanol, 2.46 ± 0.07% acetic acid, 327.89 ± 3.60 mg GAE/ L total phenolic, 2.32 ± 0.17 mg/100 mL ascorbic acid and 52.40 ± 0.23% mg AA/100 mL free-radical scavenging activity. In conclusion, vinegar-like fermented papaya beverage was successfully produced and its chemical compositions changed from papaya juice to wine and vinegar-like beverage with increased bioactive compounds and antioxidative activity

Penyahbauan fukoidan dan kesannya terhadap ciri fizikokimia dan aktiviti antipengoksidaan

Fukoidan adalah sejenis polisakarida bioaktif yang terdiri daripada fukosa, sulfat dan asid uronik. Fukoidan mempunyai bau hanyir menyebabkan aplikasi dalam produk makanan menjadi sukar. Oleh itu, objektif kajian ini adalah untuk menyahbau hanyir fukoidan yang diekstrak daripada Sargassum sp. (Fsar) dan mengkaji kesan penyahbauan terhadap ciri-ciri fizikokimia dan aktiviti antipengoksidannya. Fsar dinyahbau dengan menggunakan butiran karbon teraktif (Fkar), kaedah pengewapan haba (Fwap) dan gabungan kedua-dua kaedah tersebut (Fkw). Keberkesanan penyahbauan dikenal pasti melalui penilaian sensori (ujian deskriptif kuantitatif) bagi menilai persepsi bau fukoidan yang telah dinyahbau. Ciri fizikokimia iaitu ketulenan, warna dan nilai pH, manakala aktiviti antipengoksidaan ditentukan melalui ujian pemerangkapan radikal bebas (DPPH), aktiviti pemerangkapan superoksida anion (SOA) dan pemerangkapan radikal hidroksil (•OH). Kaedah penyahbauan Fkar menunjukkan nilai keamatan bau hanyir yang paling rendah dan tahap penerimaan keseluruhan yang paling tinggi. Ketulenan Fkar tidak berbeza secara bererti (p>0.05) berbanding Fsar, manakala ketulenan Fwap dan Fkw menurun secara signifikan berbanding Fsar. Keempat-empat sampel fukoidan (Fsar, Fkar, Fwap, Fkw) menunjukkan warna dan nilai pH berbeza secara signifikan (p0.05) terhadap kesan antipengoksidaan oleh kempat-empat sampel fukoidan selepas penyahbauan (Fsar, Fkar, Fwap, Fkw). Pada keseluruhannya, kaedah penyahbauan menggunakan karbon teraktif (Fkar) didapati berpotensi kerana keberkesanan dan tidak menyebabkan perubahan signifikan pada ketulenan dan aktiviti antipengoksidaan fukoidan