Effect of pretreatments and drying methods on physico‐chemical,sensory characteristics and nutritional value of oyster mushroom

This study was aimed to evaluate the effect of pretreatments and drying methods on the chemical, physico‐chemical, sensory characteristics and nutritional value of oyster mushroom. Chemical analysis of oyster mushroom (OM) showed that the values content were increased by many times when calculated on dry weight basis. Nine treatments of dried mushroom powders (DMP) were prepared using three drying methods (hot air drying, vacuum drying, and sun drying). Also, three pretreatments of each method of drying were used (untreated, blanching by steaming without or with steeped in 0.5% citric acid solution for 30 min).The results and statistical analysis revealed that, sun dried oyster mushroom samples (without pretreatments) were found to be the best. The DMP samples resulting of the sun drying had a highest physico‐chemical properties, sensory evaluation scores, and contents of the mineral elements and amino acids as compared to other pretreatments and drying methods.

Practical applications

Fresh mushrooms have high water content, high enzymatic activity and hence are highly perishable. Thus, in this study nine treatments of dried mushroom powders (DMP) were prepared using three drying methods (hot air drying, vacuum drying and sun drying).Also, three pretreatments of each method of drying were used (untreated, blanching by steaming without or with steeped in citric acid).The DMP samples (untreated) resulting of the sun drying were better than other pretreatments and drying methods regarding quality attributes.     

Effect of different types of maltodextrin and drying methods on physico‐chemical and sensory properties of encapsulated durian flavour

A study on durian (Durio zibethinus Murr) flavour encapsulation was conducted using three types of maltodextrin – glucose syrup solid (GSS), fieldose PHS‐15 and pasilli – and two drying methods: spray and freeze drying. Results showed that the three types of maltodextrin used in this study proved to be suitable for use in the preparation of durian flavour encapsulation. GSS, however, was shown to be the most suitable encapsulating agent in maintaining the original aroma of durian. For both physico‐chemical and sensory analyses, durian powder dried using the freeze drying method was better in terms of moisture, water activity, fat, total sugar, colour, bulk density, degree of lump, scanning electron photomicrograph microstructure and sensory attributes, including aroma, appearance and colour, compared to the durian powder dried using the spray drying method. © 1999 Society of Chemical Industry     

Microbial,physico‐chemical and sensory characteristics of mango juice‐enriched probiotic dairy drinks

This study aimed to determine whether mango juice can improve the viability of probiotics in a fermented dairy‐based beverage whilst maintaining its quality characteristics. Formulations containing Lactobacillus acidophilus La‐5 culture, whole cow's milk and varying concentrations of mango juice (0%, 10%, 20%, 30% and 40% (w/w)) were produced and stored for five weeks at 4 °C. Results showed that probiotic viability was enhanced with the addition of 10% mango juice. Additionally, this formulation improved probiotics tolerance when exposed to in vitro gastrointestinal digestion. According to the sensory analysis, beverage sensory scores improved as levels of mango juice increased from 20% to 40%.     

Effect of fat content on sensory and physico‐chemical properties of laboratory‐pasteurised calcium‐ and vitamin D‐fortified mixture of cow and buffalo milk

The influence of milk fat on physico‐chemical properties of calcium and vitamin D‐fortified milk was investigated. Sensory scores, curd tension, viscosity, rennet coagulation time and TBA value increased with the increase in fat content. Calcium and vitamin D fortification had no effect on sensory scores, whereas a significant increase was observed in curd tension and viscosity. The TBA value of fortified milk was significantly lower than that of the unfortified milk. The rennet coagulation time of milk increased significantly with addition of calcium phosphate, whereas calcium citrate fortification had no significant effect. All milk samples were stable to alcohol.     

The effect of traditional production methods on microbial,physico‐chemical and sensory properties of ‘Slovenská bryndza’ Protected Geographical Indication cheese

Bryndza is a natural, white, mature and spreadable kind of cheese, and since 2008, it has been manufactured in specified mountainous areas of the Slovak Republic with Protected Geographical Indication. The aim of this work was to provide useful information about the microbial, physico‐chemical and sensory characteristics of bryndza, taking into consideration the variabilities related to the traditional methods of production technology of three bryndza cheese varieties. Statistically significant differences were observed in bryndza cheese production methods in chemical parameters of NaCl and malondialdehyde content (P < 0.05) and in the microbial presence of Enterococcus spp. (P < 0.001) and Staphylococcus spp. (P < 0.01).     

Effect of limited enzymatic hydrolysis on physico‐chemical properties of soybean protein isolate‐maltodextrin conjugates

The effect of limited hydrolysis was investigated on the physico‐chemical properties of soy protein isolate–maltodextrin (SPI‐Md) conjugate. The hydrolysates at a degree of hydrolysis (DH) of 1.8% showed much higher surface hydrophobicity (H₀; 71.39 ± 3.60) than that of the SPI control (42.09 ± 2.17) and SPI‐Md conjugates (53.46 ± 2.74). Intrinsic fluorescence analysis demonstrated the unfolding of protein molecule and exposure of hydrophobic groups of SPI‐Md conjugate hydrolysates. As evidenced by far‐UV circular dichroism (CD) spectroscopy, the limited hydrolysis increased the unordered secondary structures of SPI‐Md conjugates. The denaturation temperature (T_d) of SPI‐Md conjugate was significantly increased by subsequent limited hydrolysis from 102.53 ± 0.60 °C to 108.11 ± 0.61 °C at DH 1.8%. In particular, the emulsifying activity index (EAI) was improved notably after limited hydrolysis of DH 1.8% (147.76 ± 4.39 m² g^?1) compared with that of native SPI (88.90 ± 1.44 m² g^?1) and SPI‐Md conjugate (108.97 ± 1.45 m² g^?1).     

Influence of sorghum grain type on wort physico‐chemical and sensory quality in a whole‐grain and commercial enzyme mashing process

To determine the most suitable types of sorghum for whole‐grain adjunct in lager beer brewing, 14 cultivars of five different types: white tan‐plant, white non‐tan‐plant, red non‐tannin, white tannin (type II) and red tannin (type III) were evaluated. The effects of grain type on wort physico‐chemical and sensory quality with raw grain and malt plus commercial enzyme mashing were assessed. Tannin content correlated significantly and negatively with wort extract and fermentable sugars (p < 0.001) and free amino nitrogen (FAN; p < 0.1). This is attributable to inactivation of the exogenous enzymes by the tannins during the mashing process. However, the type II tannin sorghums had wort quality attributes closer to the non‐tannin sorghum types, probably owing to their relatively low tannin content (≤1%). Malting gave a great improvement in wort extract, fermentable sugars and FAN, but substantially influenced wort sensory properties in terms of higher sourness, bitterness and astringency, as well as the expected more malty flavour. Worts from raw red non‐tannin sorghums were similar to those of white tan‐plant sorghums in both physico‐chemical and sensory quality. Thus, red non‐tannin sorghums, in view of their better agronomic quality, have considerable potential as a whole‐grain adjunct in lager beer brewing. Copyright © 2013 The Institute of Brewing & Distilling     

Omega‐3 fatty acid‐fortified butter: Preparation and characterisation of textural,sensory, thermal and physico‐chemical properties

The influence of adding flaxseed oil (2.9–5.1%) and flaxseed–whey protein concentrate (WPC) emulsion (4.8–8.6%) to cream as an omega‐3 fatty acid source was evaluated on the thermal, sensory and physico‐chemical properties of the developed butter. Pulsed nuclear magnetic resonance analysis revealed lower saturated fat content in the fortified butter than control butter. Differential scanning calorimetry exotherms and endotherms also corroborated these findings. Fortified butter prepared with 6.8% flaxseed oil–WPC emulsion had 3.7 times more alpha‐linolenic acid content than control and provided nearly 25% of the recommended dietary allowance in one serving. The developed butter exhibited improved spreadability.     

Impact of β‐glucan and other oat flour components on physico‐chemical and sensory properties of extruded oat cereals

Whole oat flour, N979‐5‐2‐4 (N979), IA95111 (IA95), ‘Jim’ and ‘Paul’ with β‐glucan concentration of 8.6%, 7.6%, 5.3%, and 5.9%, respectively, was made into extruded breakfast cereal (EBC). EBC β‐glucan had greater peak molecular weight than corresponding whole oat flour. Both whole oat flour and EBC from N979 and IA95 had greater peak viscosity (PV), as measured using a Rapid ViscoAnalyser, than that from Jim or Paul. Bile acid binding of EBC, correlated with total β‐glucan concentrations and PV, was either similar or greater than that of corresponding whole oat flour. Jim EBC had the least expansion ratio, lowest brown colour and cereal aroma but greatest tooth packing values. Paul and N979 EBC, although different from each other in a few sensory attributes, had similar acceptability as judged from a consumer test, suggesting that oats with elevated β‐glucan concentrations can be successfully incorporated into EBC with minimal processing alterations.     

Phenolics and physico‐chemical characteristics of persimmon during post‐harvest storage

Garden picked mature but unripe fresh persimmon fruits were unipackaged in different thicknesses of polyethylene (PE) and stored at room (18.5–30°C) and refrigerated temperature (6 ± 1°C). Maximum mean methanol extractable sinapine (0.168%( catechin (1.51%( and leucoanthocyanidine (10.94 ΔA550/g) were recorded in the unipackaged samples kept at room temperature during 6 weeks storage, whereas the minimum values for water extractable phenolics (sinapin, catechin and procyanidin) were recorded in unipackaged samples under refrigerated temperature. The mean maximum weight loss of 12.58 and 7.90% was recorded in control samples kept at room temperature and low temperature, respectively. The weight loss for unipackaged in different thicknesses of PE ranged between 0.93–0.96% and 0.43–0.45% for samples kept at room and low temperature, respectively. Changes in texture values were significantly faster in control than unipackaged samples (P < 0.05). Low temperature combined with unipackaging in PE film performed better for the maintenance of overall fruit quality during post‐harvest storage.     

Effects of tangential microfiltration and pasteurisation on the rheological,microbiological, physico‐chemical and sensory characteristics of sugar cane juice

The aim of this study was to determine the physico‐chemical, microbiological, rheological and sensory characteristics of sugar cane juice with passion fruit pulp (5% w/w) added and which had been submitted to microfiltration and pasteurisation (90 °C/30 s; 95 °C/30 s) processes. The results showed that the juices obtained after the microfiltration and pasteurisation processes had low microbial counts. The microfiltered juice showed a reduction in the soluble solids, acidity and vitamin C content (P = 0.05), while the pasteurised juice showed no change in these parameters (P > 0.05) in relation to the natural sugar cane juice, with the exception of vitamin C, which was not detected after the thermal treatment. In relation to the rheological properties, Newtonian behaviour was observed for both microfiltered and pasteurised juices. The sensory tests on a hedonic scale showed good acceptance of both juices (microfiltered and pasteurised).