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     

Phenolic content,antioxidant and physico‐chemical properties of Sardinian monofloral honeys

In this study, fifty‐one monofloral Sardinian honeys from ten various floral origins were screened for their phenolic content, antioxidant activity, colour and electrical conductivity. The total phenolic amounts have been evaluated by Folin–Ciocalteu method, whereas quantification of several phenolic compounds (phenolic acids and flavonoids) has been carried out by HPLC‐DAD technique. The richest sample in phenolic compounds resulted strawberry tree honey with about 40 mg GAE/100 g, as well FRAP test and DPPH˙ test confirm that antioxidant activity of strawberry tree honey extract exceed both honey extracts and synthetic antioxidants like BHA and BHT. Among the studied phenolic compounds a total of five phenolic acids (ferulic, syringic, trans‐cinnamic, chlorogenic and p‐hydroxycinnamic) and nine flavonoids (catechin, kaempferol, rutin, quercetin, luteolin, apigenin, galangin, pinocembrin and pinobanksin) were identified. Our results show good correlations between total polyphenol amount and antioxidant activity and between colour and electrical conductivity.     

Aroma profile and physico‐chemical properties of artisanal honey from Tabasco,Mexico

The aim of this work was to characterise, physico‐chemically, sugar composition and aroma profile of ten honey samples collected by small producers during two seasons and produced in different agricultural ecosystems from Tabasco State (Mexico). The mean values obtained for the physico‐chemical parameters were: pH 3.63; 19.25% moisture; 78.8°Brix sugar; 0.64% ash; 0.25 mS cm^?1 electrical conductivity and 0.58 water activity. Based on colour parameters, Tabasco honeys can be placed in the group of dark honeys. In the analysed samples; fructose was the major sugar (39.45%), followed by glucose (35.74%) while sucrose only represented 2.93%. The volatile profiles of the ten honey samples were obtained by gas chromatography‐mass spectrometry. All the honeys were characterised by their high contents of benzene and furan‐related compounds. As a result, artisanal honeys from Tabasco (Mexico) can be considered to present a good level of quality.     

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 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).     

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.     

Evaluation of physico‐chemical properties,trace metal content and antioxidant activity of Indian honeys

In this study, effect of plant sources viz. Gossypium hirsutum, Coriander sativum, Murraya koenigii and Dalbergia sisso on twelve physico‐chemical properties, phenolic content, flavonoids content as well as on trace mineral (Fe, Cu, Ni, Mn, Cd and Pb) contents of honey were investigated and compared. All the physico‐chemical values were in the range of approved limits of European Commission Regulation and the source of honey had a significant (P < 0.05) effect on physico‐chemical properties, phenol content, flavonoid content and trace mineral content. The results of positive correlations between physico‐chemical properties (colour and antioxidant properties) and compositional components (phenols and flavonoids content) established that antioxidant properties were dependent on source of honey rather than on colour of honey. Pattern recognition methods such as principal component analysis and linear discriminate analysis were performed to classify honey on the basis of physico‐chemical properties, phenolic content, flavonoids content and trace metal content. The variables proline and lead exhibited higher discrimination power.     

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 micronization on the physico‐chemical properties of peels of three root and tuber crops

BACKGROUND: The aim of this study was to investigate the effect of micronization on the physicochemical properties of the peels of root and tuber crops, including yam (Dioscorea alata L.), taro (Colocasia esculenta L.) and sweet potato (Ipomea batatas L.). Two continuous milling sections, including hammer milling and ball milling, were applied to three samples to obtain micro‐sized particles of root and tuber peels. The micronization by ball‐milling treatment for 10 h was carried out to investigate the distribution of particle sizes and the changes in physiochemical properties. RESULTS: The results indicate that the peels of three crops appeared to be significantly decreased in particle size after 10 h of ball‐milling treatment. Moreover, the ball‐milling treatments resulted in the redistribution of fiber components from insoluble fiber to soluble fiber. The micronization treatments decreased the bulk density but increased the solubility and water‐holding capacities of the micronized peels. CONCLUSION: Our findings suggested that micronization treatments can improve functional properties of the fiber components of micronized peels, which provide a good source of dietary fiber in food applications. Copyright © 2010 Society of Chemical Industry     

A comparison of the physico‐chemical properties of low‐cholesterol ghee with standard ghee from cow and buffalo creams

Low‐cholesterol ghee with 90% less cholesterol was prepared using β‐cyclodextrin. The physico‐chemical properties such as Reichert‐Meissl (RM) value, Polenske value, Butyro‐refractometer (BR) reading at 40°C, Iodine value and free fatty acids (FFA) as oleic acid in cow standard ghee and the corresponding low‐cholesterol ghee remained almost unaltered. A similar trend was also observed in buffalo ghee. Fat soluble vitamins (β‐carotene, A and E) in both cow and buffalo low‐cholesterol ghee were very similar to that of respective standard ghee samples. However, 65 to 70% loss of vitamin D was observed in low‐cholesterol ghee.     

Rheological and physico‐chemical properties of gelatin extracted from the skin of a few species of freshwater carp

The physico‐chemical and rheological properties of gelatin from the skins of three different freshwater carp species, namely Catla catla, (catla) Cirrhinus mrigala (mrigal) and Labeo rohita (rohu), have been assessed and compared with that of gelatin from porcine skin. The average solids yield from the three species of carp varied in the range of 11.8–14.1%. The amino acid profile showed that the porcine gelatin had a higher proportion of imino acids and glycine than carp skins gelatin. The average molecular weight of carp skins gelatin as determined using a gel filtration technique was 233 kDa, while that of porcine skin gelatin was 282 kDa. The gelling temperature of carp skins gelatin was in the range of 6–15.7 °C, and the melting temperature was 17.9–23.7 °C as determined using a controlled stress rheometer. A higher gelling and melting temperature was observed for porcine skin gelatin.     

Skin hydration effects,physico‐chemical properties and vitamin E release ratio of vital moisture creams containing water‐soluble chitosans

Synopsis The effects of the addition of water‐soluble chitosans on skin hydration, physico‐chemical properties and vitamin E release ratio of vital moisture creams (vitamin E‐containing creams) were studied. Results show that vitamin E‐containing creams containing different molecular weights and/or concentrations of water‐soluble chitosans are pseudoplastic fluids. The apparent viscosity of vitamin E‐containing creams increased with increasing molecular weight and/or with increasing concentration of water‐soluble chitosans used in the formula. The apparent viscosities of those vitamin E‐containing creams containing 0.5% water‐soluble chitosan were higher than those containing 2% glycerol monostearate (control). The higher apparent viscosity of vitamin E‐containing creams obtained using water‐soluble chitosans improves the stability and enhances skin hydration of the creams thus prepared. Such creams containing water‐soluble chitosans were stable for more than 3 months during high temperature or cyclic temperature storage, whereas those containing glycerol monostearate had a shorter storage life of 2 months. Skin hydration in terms of water‐holding capacity of vitamin E‐containing creams containing 1.0% water‐soluble chitosan was superior to those containing 2% glycerol monostearate. No erythema occurred on shaved rabbit skin after applying vitamin E‐containing creams containing water‐soluble chitosans, and the vitamin E release ratios of these creams were similar to the cream containing 2% glycerol monostearate. Résumé Nous avons étudié le rôle de l’addition de chitosanes hydrosolubles dans une crème hydratante vitale, sur le taux de relargage de vitamine E, l’hydratation de la peau et les propriétés physiscochimiques de cette préparation. Les résultats montrent que les crêmes hydratantes vitales contenant différentes masses moléculaires et/ou concentrations de chitosanes hydrosolubles sont des fluides pseudo‐plastiques. La viscosité apparente des crêmes hydratantes vitales croit avec la masse moléculaire et/ou la concentration des chitosanes employés dans la formulation. La viscosité apparente de ces crèmes hydratantes vitales contenant 0.5% de chitosane hydrosoluble est supérieure à celle contenant 2% de monostéarate de glycérol (contrôle). La viscosité apparente plus élevée des crêmes hydratantes vitales obtenue grâce à la présence de chitosane hydrosoluble améliore la stabilité, accroit l’hydratation de la peau. Les crêmes hydratantes vitales contenant du chitosane hydrosoluble sont stables pendant 3 mois au cours d’un stockage à température élevée, en continu ou cyclique. Ceux contenant du monostéarate de glycérol ont une durée de conservation inférieure, de 2 mois. L’hydratation de la peau, en terme de capacité de rétention d’eau, pour les crêmes hydrantes vitales contenant 1% de chitosane hydrosoluble sont supérieures à celles contenant 2% de monostéarate de glycérol. Aucun érythème n’apparait sur une peau de lapin rasé après application de crême hydratante vitale contenant des chitosane hydrosolubles. Le taux de relargage de vitamine E des crêmes hydratantes vitales contenant des chitosanes hydrosolubles est semblable à celui des crêmes contenant 2% de monostéarate de glycérol.     

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%.