Corona Discharge Power of Plasma Treatment Influence on the Physicochemical and Microbial Quality of Enoki Mushroom (Flammulina velutipes)

Plasma treatment was widely known as an effective technology applied for contact-surface decontamination. Enoki (Flammulina velutipes) was an edible-medicinal mushroom with different phytochemicals and bioactive components beneficial for human health. Enoki mushroom had high respiration rate therefore it was highly perishable after harvesting. Moreover, it was greatly susceptible to microbial contamination but it was not feasible to be decontaminated by normal water washing. It’s urgent to extend shelf-life and control microbial criteria on this mushroom in dry manner without aqueous treatment. Corona discharge plasma was among 4 kinds of diverse cold atmospheric pressure plasma sources widely applied in food industry. This study demonstrated the influence of corona discharge plasma power values (control, 120, 150, 180, 210 W) on the physicochemical and microbial characteristics of Enoki mushroom during 10 days of storage at ambient temperature. Results showed that Enoki mushroom should be treated at 150 W of corona discharge plasma power to retain weight loss, total soluble solid, vitamin C in acceptable values while reducing total Aerobic count, Coliform, Enterobacteriaceae as much as possible. At the 10th day of storage, the weight loss, total soluble solid, vitamin C, total Aerobic count, Coliform, Enterobacteriaceae were recorded at 3.35±0.07%, 6.98±0.03 oBrix, 14.81±0.04 mg/100 g, 4.71±0.05 log CFU/g, 3.17±0.02 log CFU/g, 2.13±0.01 CFU/g, respectively. Findings of this research proved that corona discharge plasma pretreatment would be appropriate to maintain physicochemical properties and retard microbial loads on Enoki mushroom during preservation.

Effects of Microbiological and Physicochemical Properties of Cow’s Milk and Goat’s Milk Dadih Inoculated with Various Lactobacillus Species

Dadih is a dairy-based product and it is one of the most popular desserts among Malaysians and Indonesians. It is made from raw milk which naturally contains various types of microorganisms. This study was conducted to develop cultured dadih by inoculating various Lactobacillus species such as Lactobacillus acidophilus, Lactobacillus plantarum and Lactobacillus paracasei into dadih made from cow’s milk and goat’s milk. Prior to isolation of LAB from control dadih (dadih without inoculation with LAB), the dadih was stored at 4˚C for 48 hours. The microbiological (general microbial load, viability of and LAB, mould and yeast count) and physicochemical properties (pH, lactic acid content, total soluble solid, colour, texture and proximate composition) of dadih with different LAB strains and without LAB strain were determined. Results showed that L. paracasei spp. paracasei, Lactobacillus brevis, Lactobacillus casei were isolated from cow’s milk dadih while only L. paracasei spp. paracasei was isolated from goat’s milk dadih. The number of LAB ranged from 5.73 to 6.06 log10 CFU/g for cow’s milk dadih and 5.19 to 5.88 log10 CFU/g for goat’s milk dadih. Results revealed that dadih inoculated with LAB has lower pH and greater amount of lactic acid produced than control dadih. Total soluble solid for dadih with LAB also decreased. Hardness of dadih without LAB culture was higher compared to the inoculated dadih with LAB cultures. Proximate compositions (moisture, ash, crude fat, crude protein and total carbohydrate) showed variations due to differential formulations and incorporations of different LAB strains. Findings showed that L. acidophilus was chosen as the best starter culture for both types of dadih because it has significant effects on pH, titratable acidity, total soluble solid and texture of the dadih.

Biosynthesis and characterizations of extracellular enzymes of microbial isolates from dairy industrial effluent

Diary effluents are environmental pollutant which could serve as source of substrate for microbial enzymes' synthesis. This research investigated the isolation and screening of bacteria and fungi with potential extracellular proteolytic and amylolytic properties from dairy effluents, and their characteristics for maximum enzyme production. Effluent from a dairy industry located in Ibadan, Nigeria, was collected for isolation and screening of microbial species for enzymatic activities. The Biological Oxygen Demand (BOD), Total Soluble Solid (TTS), and pH of the effluent were determined using standard procedures. The potential isolates were characterized morphologically and by molecular techniques. Proteolytic and amylolytic activities of isolates were investigated on skimmed milk starch agar respectively and optimized with varying pH (6.0 - 9.0), temperature (27 - 60 °C) and incubation period (12 - 72 h). Data were analyzed by Duncan Multiple Range Test. Biological Oxygen Demand, Total Soluble Solid and pH of the effluent were 14.67 mg/L, 13.33% and 7.58 respectively. Eleven isolates were positive for either protease or amylase synthesis, but only two showed both proteolytic and amylolytic activities and were molecularly characterized as Bacillus stratosphericus CM2HG6 and Aspergillus welwitschiae. Optimization showed that enzyme production by B. stratosphericus CM2HG6 was highest at 35 °C, pH 7.0 for 48 h, and that of A. welwitschiae achieved optimum production at 37 °C, pH 8.0 for 72 h. Under optimized conditions, Bacillus stratosphericus CM2HG6 was the highest amylase and protease producer (24.4 and 30.74 U/ml respectively), while A. welwitschiae was the lowest producer (12.58 and 18.8 U/ml respectively). The study successfully showed that these industrially-important enzymes can be produced by microbial strains isolated from dairy effluent, and production can be further optimized

Effectiveness of CaCl2 treatment on quality attributes of banana fruit during storage

Banana is a delicious fruit with excellent nutrient components beneficial for human health. In postharvest, banana fruit is quickly ripe within few days at ambient temperature condition and its quality is seriously degraded afterwards. Extension of its stability during storage and distribution is very necessary to enhance its economic value. This research evaluated the effectiveness of CaCl2 treatment on the physicochemical quality attributes, phyto-chemical and antioxidant activities, and potential enzymes of banana fruit during storage. Banana fruits were dipped in 3% CaCl2 solution for 5 min before draining on racks for 30 min at ambient temperature to remove excess calcium chloride solution. Another banana group is dipped in clean water, leaved on racks for 30 min as the control. Both these fruit groups were then stored at 4±0.5oC with 85-90% relative humidity for 28 days. In 7 day-interval, each group is taken to verify quality attributes such as decay index, firmness, extractable juice recovery, ascorbic acid, carotenoid, total soluble solid, phenolic content, total flavonoid content, DPPH radical scavenging rate, H2O2 content, catalase (CAT) activity, superoxide dismutase (SOD) activity of banana fruit during storage. Our findings demonstrated that CaCl2 exerted a positive influence in limiting decay (2.24±0.11 mark); slowing down texture firmness reduction (7.25±0.10 N); enhancing the extractable juice recovery (85.49±1.12%); controlling ascorbic acid (12.79±0.13 mg/100 g), total soluble solid (16.40±0.13 oBrix), phenolic retention (161.35±1.19 mg GAE/100 g), flavonoid content (64.41±0.25 mg QE/100 g) and H2O2 accumulation (20.09±0.10 µmol/g); improving carotenoid (21.83±0.13 µg/100 g), catalase (15.28±0.12 U/g), superoxide dismutase activity (5.60±0.10 U/g), antioxidant capacity of banana fruit (46.20±0.15%) during chilling storage. CaCl2 treatment would be an effective approach to extend shelf life of banana fruit in commercial distribution.

Optimization of Fermentation Conditions for Production of Hungarian Sour Cherry Spirit Using Response Surface Methodology

Pálinka is a traditional fruit spirit and a kind of gastronomic heritage in Hungary. In Pálinka production, fermentation is one of the most important processes affecting the quality and yield of spirits. Based on single-factor and three-factor influence level tests by following the Plackett–Burman design, the fermentation process from sour cherry juice concentrate and Saccharomyces cerevisiae by using Response Surface Methodology (RSM) coupled with the central composite rotatable design was investigated to optimize fermentation conditions through three variables in a defined range of temperature (1525 °C), pH (2.753.75), and total soluble solid (1830 °Brix). After eight fermentation days, production yields of alcohol and volatile compounds were a maximum of 9.02% v/v and 337.37 mg/L at an optimized temperature of 24.71 °C, pH of 3.25, and total soluble solid of 22.49 Brix. The GC-FID analysis results showed 1-propanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and ethyl acetate were considered the major aroma compound in the cherry spirits. These results provided important information in serving the basic to develop standard fruit spirits production from sour cherry.

Study on Factors Affecting Physicochemical Properties of Spray Dried Mango Powder Using Taguchi Experimental Design Approach

Mango is a common fruit in tropical countries. Due to its short shelf-life, it is important to study alternative preservation and consumption methods. In this study, concentrated mango juice was used to produce mango powder by using spray drying process. Four process parameters with three levels variation each, including initial total soluble solid content (13, 14, 15◦Brix), maltodextrin content (20, 25, 30% w/w), inlet air temperature (170, 190, 210◦C), and atomization pressure (4, 5, 6 bar) were studied. Taguchi approach of L-9 (34) array was used to design the experiments. Powder yield, moisture content, color difference, and solubility of the mango powder were investigated. It was found that maltodextrin content was the greatest factor affecting powder yield and color difference. The highest powder yield was 31.81%, and the least color difference (∆E) was 3.17. Inlet air temperature and atomization pressure were the most important factor affecting to moisture content and solubility, respectively, in which average moisture content was 2.98% (w.b.) and the highest solubility value was 94.66%. For the overall production process, it was concluded that maltodextrin content was the most important parameter, while total soluble solid content provided the least impact on spray dried mango powder properties.

Formulasi Pembuatan Minuman Herbal dari Campuran Sari Jahe dan Temulawak

Penelitian ini bertujuan untuk menghasilkan produk minuman herbal yang diperkaya dari sari jahe dan temulawak. Selain itu juga bermanfaat sebagai acuan dalam pembuatan minuman herbal dari campuran jahe dan temulawak. Penelitian ini dilakukan di laboratorium Pengolahan dan Pengelolaan Hasil Pertanian Fakultas Pertanian Universitas Katolik Santo Thomas. Penelitian ini dilakukan dengan Rancangan Acak Lengkap (RAL) faktorial, yang terdiri dari dua faktor perlakuan. Faktor pertama konsentrasi tepung kedelai dengan sandi J, terdiri dari 4 taraf, yaitu: Jo=80:20, J1= 70:30, J2= 60:40, dan J3= 50:50. Faktor kedua lama pengeringan dengan sandi L, terdiri dari 4 taraf, yaitu: L0= 0 minggu, L1=1 minggu, L2= 2 minggu; dan L3= 3 minggu. Perlakuan perbandingan konsentrasi jahe dan temulawak berpengaruh sangat nyata terhadap keempat parameter ini yaitu total soluble solid (tss), pH, nilai total asam, dan uji organoleptik. Perlakuan lama penyimpanan (0 minggu, 1 minggu, 2 minggu, dan 3 minggu) berpengaruh sangat nyata terhadap keempat parameter ini yaitu total soluble solid (tss), pH, nilai total asam, dan uji organoleptik. Untuk total soluble solid (tss), dan nilai total asam mengalami peningkatan pada grafiknya, sedangkan pH dan uji organoleptik mengalami penurunan pada tiap minggunya. Dan untuk kombinasi perlakuan perbandingan konsentrasi jahe dan temulawak berpengaruh sangat nyata uji organoleptik, tetapi berpengaruh tidak nyata terhadap total soluble solid (tss), pH dan nilai total asam