Influences of food matrices on cytotoxicity of asiatic acid in mammalian cell models

This study investigated the cytotoxicity of asiatic acid (AA) encapsulated in different protein‐carbohydrate matrices in human colon adenocarcinoma SW620, human hepatoblastoma HepG2 and diploid monkey kidney cells (Vero). Mungbean protein concentrate (MPC) and mungbean protein hydrolysate (MPH) in lactose (L) or lactose‐maltodextrin (LM) mixture, were used to fabricate matrices encapsulating AA during lyophilisation. The cytotoxicity of AA was in a dose‐dependent manner for HepG2 and SW620 cells, but not for Vero cells. The 50% inhibitory concentrations (IC₅₀) of AA in HepG2 and SW620 were 120 and 130 μm respectively. The IC₅₀ of AA encapsulated in MPH‐L matrix in HepG2 was reduced from that of AA alone to 80 μm (P < 0.05). Study of the anti‐cancer activity of AA, in the absence and presence of food matrices, revealed that an MPH‐L matrix led AA to cause more apoptosis deaths in HepG2 cells than either a MPC‐L matrix or pure AA.     

The Associations Between Oral Complex Carbohydrate Sensitivity,BMI, Liking,and Consumption of Complex Carbohydrate Based Foods

Recent work suggests that humans may perceive complex carbohydrates and that their sensitivity to simple carbohydrates (i.e., glucose and sucrose) is independent from tasting complex carbohydrates. The aim of this study was to confirm whether humans could sense complex carbohydrates from a range of concentration levels; and if their oral sensitivity to complex carbohydrate relates to their BMI, liking, and consumption of complex carbohydrate‐based foods using a large sample group of adults. Participants’ (n = 92 females, age 23.7 ± 0.5 yr [range, 19 to 47 yr]) oral sensitivity towards complex carbohydrate (maltodextrin) and sweet taste function (glucose) was assessed by measuring detection threshold and suprathreshold intensity perception (gLMS). Participants were asked to complete an online version of a Food Frequency Questionnaire and a Likes and Dislikes Questionnaire. Hedonic ratings for complex carbohydrate and sweet solutions, as well as for a range of complex carbohydrate and sweet prototypical foods, were also measured. Consistent with previous findings, there was large interindividual variation in detection and intensity measures for maltodextrin and glucose. No significant associations were found between oral complex carbohydrate sensitivity, Body Mass Index (BMI), and frequency of consumption of complex carbohydrate‐based foods measured. Similarly, no differences were observed between liking of complex carbohydrates, BMI, and food intake. All in, these results from a large sample group further support the proposition that complex carbohydrates are not invisible to the human palate, and can be sensed in the oral cavity even at low concentration levels.     

Spray‐drying encapsulation of citral in sucrose or trehalose matrices: physicochemical and sensory characteristics

The potential of the disaccharide trehalose as carrier for producing spray‐dried citral was examined. Some physical and sensory characteristics of citral encapsulated in matrices containing either trehalose or sucrose and maltodextrin (MD) were analysed. They included water sorption, glass transition temperatures (T_g), nuclear magnetic resonance (NMR) relaxation and citral retention during spray‐drying. The glassy state at room temperature (25 °C) was maintained as far as 33% relative humidities (RH) for the spray‐dried trehalose formulation and 43% RH for trehalose–MD; however, for sucrose–MD and for sucrose formulations, the glassy state was limited to RHs lower than 33% and 22%, respectively. Sensory evaluation and gas chromatographic analysis indicated that citral retention after spray‐drying was similar for matrices containing either trehalose or sucrose. However, trehalose formulations had improved physical stability as compared to sucrose.     

Impact of trehalose,sucrose and/or maltodextrin addition on aroma retention in freeze dried strawberry puree

Trehalose was studied as a drying aid to establish its impact on aroma retention in freeze dried strawberry puree. The evaluation was done by sensory analysis and headspace‐solid phase microextraction‐gas chromatography with a mass detector (HS‐SPME‐GC‐MS); results were compared with those obtained using sucrose and maltodextrin (MD) as drying aids. The carbohydrate used significantly modified the type and concentration of volatiles retained during freeze drying. HS‐SPME‐GC‐MS outcomes showed that the use of trehalose (alone or with MD) resulted in the product with the chromatographic profile most similar to fresh strawberry puree, being different from sucrose and MD. Meanwhile, sensory analysis showed a similarity with the aromatic profiles when using trehalose or sucrose, remaining both different from MD. This study proved that the use of trehalose as a drying aid can be beneficial on volatile aroma retention and that different combinations of organic volatiles can lead to similar sensory profiles.     

Effect of Processing of Sword Beans (Canavalia gladiata) on Physicochemical Properties of Starch

The effect of various processing methods on physico‐chemical properties of sword bean starch was studied. Seed grits and flour were cooked with and without soaking, wet‐autoclaved, and roasted. The changes in starch associated with these processing methods were studied by observing changes in granular structure, water solubility index, water absorption index, molecular size distribution and the degree of gelatinization estimated by differential scanning calorimetry. Intact, ungelatinized starch granules of raw and dry‐heat treated samples were observed under the light microscope. The starch granules were elliptical in shape and had an average length and breadth of 37–40 μm and 27 μm, respectively. Wet‐processed samples had the lowest water solubility, higher water absorption and lower gelatinization enthalpies than the raw bean flour, whereas the dry heat‐treated samples showed higher water solubility and higher gelatinization enthalpies. The starch molecular size distribution pattern showed a higher amount of high molecular size carbohydrates in dry heat‐treated samples and a large fraction of intermediate molecular size carbohydrates in the wet‐processed samples. The low molecular size carbohydrate content was low in wet‐processed samples where processing was done with excess water.     

Edible packaging from hydroxypropyl thermoplastic cassava starch,agar and maltodextrin blends produced by cast extrusion

Edible packaging from hydroxypropyl cassava starch with different degrees of substitution (DS), agar and maltodextrin films was produced by conventional cast extrusion. Microstructures showed hydrophobic agar aggregates (100–200 µm) dispersed in film matrices, giving nonsmooth surfaces that enhanced wettability (17%–31%). Higher DS increased interaction between agar and maltodextrin via hydrogen bonding due to greater plasticisation and enhanced formation of agar networks. Lower DS starch showed instability with lower tensile strength (23% of higher DS), giving poor processability that was greatly improved by agar (20%). Water vapour and oxygen permeability depended on microstructures and hydrophilic–hydrophobic properties of the matrices which were decreased by 25% and 58% with combined agar and maltodextrin, respectively. Crystallinity of the films depended on plasticisation, with enhanced mobility that reduced transparency. Agar and maltodextrin inhibited recrystallisation of starch. Findings suggested that higher DS starch and agar enhanced extrusion processability, while maltodextrin increased plasticisation and reduced network strength.     

Characterization of Physical and Mechanical Properties of Miscible Lactose‐Sugars Systems

Lactose‐sugars systems were produced by spray drying. They were lactose, lactose–glucose (4:1) mixtures, lactose–maltose (4:1) mixtures, lactose–sucrose (4:1) mixtures, lactose–trehalose (4:1) mixtures, and lactose–corn syrup solids (CSS) (4:1) mixtures. The physical characteristics, water sorption behavior, glass transition, and mechanical properties of miscible lactose‐sugars systems were investigated. Lactose–glucose mixtures had larger particle size than other lactose‐sugars systems after spray drying. The presence of glucose or sucrose in lactose‐sugars mixtures decreased the glass transition temperatures of amorphous systems, while the presence of maltose and trehalose had only minor impact on the glass transition temperatures. Moreover, glucose accelerated the crystallization of amorphous system at 0.44 a_w, but its presence delayed the loss of sorbed water at higher water activities (≥0.54 a_w). Mechanical property study indicated that glucose and sucrose in amorphous system could result in an increase of molecular mobility, while the presence of CSS could decrease the free volume and maintain the stiffness of the miscible systems.     

Rheological,thermal properties,and gelatinization kinetics of tapioca starch–trehalose blends studied by non‐isothermal DSC technology

In this paper, we studied the effects of trehalose on the rheological and thermal properties of tapioca starch (TS). Temperature sweep experiments showed that trehalose shifted the peak gelatinization temperature (T_G′max) to higher value. Rheological features calculated from the power law model indicated that trehalose addition increased the consistency and decreased the thixotropy of TS gels. DSC experiments showed that trehalose retarded the gelatinization of TS–trehalose blends reflected in the increase of gelatinization temperature. The gelatinization kinetics was evaluated by a non‐isothermal technique based on the DSC endotherms. Kinetics analysis showed the addition of trehalose increased the activation energy and decreased the rate constants of TS–trehalose blends, indicating the same sugar effect as the rheological and DSC experiments. The work demonstrated that kinetics analysis could provide new evidences for the influence of trehalose on starch gelatinization.     

Physicochemical properties and storage stability of spray‐dried soya bean sprout extract

Amylase is a very important enzyme due to its wide food applications. To preserve amylase activity in soya bean sprout extract (SSE), SSEs were spray‐dried with 10% maltodextrin and 0–3% alginic acids, and their physicochemical properties and storage stability were compared with freeze‐dried one. SSE exhibited maximum amylase activity at pH 7.0 and 60 °C, with the most active substrate specificity towards soluble starch. Spray‐dried SSEs exhibited higher water solubility index (WSI) and in vitro relative amylase activity but lower water vapour sorption (WVS) and smaller particle size than freeze‐dried SSE. For spray‐dried SSEs, particle size, WSI and in vitro relative amylase activity increased while WVS decreased with increasing % alginic acid. This study demonstrated that spray drying of SSE, especially with 10% maltodextrin and 2% alginic acid, was effective in keeping amylase active and stable during 7‐week storage at room temperature (25 °C).     

Modifications of Urethane-Foam Formulations Using Zea mays Carbohydrates

Four carbohydrates derived from Zea mays (corn), ordinary cornstarch, two high-amylose starches (one instant starch), and canary dextrin, were substituted partially (8–30%) for polyether polyol in rigid polyurethane foams. Because of different carbohydrate water contents the level of substitution was chosen for each carbohydrate to maintain uniform water contents in the foams. In addition, a lower level of canary dextrin was added to one formulation to evaluate the effect of water addition. With the exception of the dextrin-filled foams, which were similar in density to the controls, the carbohydrate-filled foams were more dense (0.0280–0.0296 versus 0.0272 g/cm³). Substitution of 8% of the polyether polyol with Amalean I (high-amylose starch) increased the density by 9%. With 15–16% substitution of the polyether with instant starch or dextrin, the compressive strength values of the foams were 10–16% lower than for the control foams. Exchanges of 8–16% polyether with any of the four carbohydrates resulted in 3–4% and 4–5% increases in volumes after 14 days of accelerated aging under thermal (70°C, ambient RH) and humid (38°C. 97% RH) conditions, respectively. The lowest priced carbohydrate, cornstarch, substituted at the 10% level for the polyether provided foams exhibiting 4% less compressive strength and similar insulating value than the control foams without carbohydrate. Since the polyether polyol is ten times more expensive than cornstarch, further study of utilizing corn-derived carbohydrates as polyols in foam formulation is merited.     

Original article: Encapsulation of ascorbic acid in amorphous maltodextrin employing extrusion as affected by matrix/core ratio and water content

Ascorbic acid (AA) was encapsulated in glassy low‐dextrose equivalent maltodextrin matrix by extrusion. The effects of formulation parameters, i.e., core/matrix ratio and water content were mainly investigated on T_g of extrudate. The AA yield, AA content and water content of the products together with extrusion parameters were also determined and compared for different formulations. The T_g of extrudates containing water content from 7.860% to 10.430% ranged from 43.17 to 27.48 °C, and the T_g of extrudates which core to matrix from 1:4 to 1:8 ranged from 35.79 to 41.64 °C. AA yield of all extrudates is above 96%, and with increasing water content, there was a slight decrease in the AA yield. The increased water level and core/matrix ratio reduce specific mechanical energy and die head pressure. X‐ray diffraction and scanning electron microscopy suggested that AA was most likely molecularly dispersed within the maltodextrin indicating the miscibility of AA and maltodextrin.     

Proximal composition and in vitro digestibility of starch in lima bean (Phaseolus lunatus) varieties

BACKGROUND: Beans are rich and inexpensive sources of proteins and carbohydrates around the world, but particularly in developing countries. However, many legume varieties are still underutilized. In this study, physical characteristics of the seeds of three Phaseolus lunatus cultivars were characterized. Also, the chemical composition and starch digestibility in the cooked beans were assessed. RESULTS: ‘Comba floja’ variety exhibited the highest thousand‐kernel weight whereas the lowest was found in ‘comba violenta’. This agrees with seed dimensions: ‘comba floja’ had the Longest seeds (16.36 mm) and ‘comba violenta’ the shortest ones (13.98 mm). All samples exhibited high protein content, but levels in ‘comba blanca’ variety (216 g kg^?1) were lower than the in other two cultivars. Total starch (370–380 g kg^?1) and potentially available starch content (330–340 g kg^?1) were similar in the three varieties. Resistant starch level in the cooked seeds ranged between 38 and 45 g kg^?1. Low enzymatic hydrolysis indices (HI) were recorded (30.2–35%), indicating a low digestion rate for Phaseolus lunatus starch. HI‐based predicted glycemic indices ranged between 34% and 39%, which suggests a ‘slow carbohydrate’ feature for this legume. CONCLUSION: Phaseolus lunatus beans appear to be a good source of protein and slow‐release carbohydrates with potential benefits for human health. Copyright © 2007 Society of Chemical Industry     

Production of Trehalose from Starch by Maltose Phosphorylase and Trehalose Phosphorylase from a Strain of Plesiomonas

The cooperative concomitant action of maltose phosphorylase (MP), trehalose phosphorylase (TP), β-amylase and a starch debranching enzyme (pullulanase, isoamylase) was investigated to develop a more efficient method for preparing trehalose from starch. About 40 and 51—56% as solid basis of 25% (w/v) liquefied potato starch were converted to trehalose by the combination of soybean β-amylase and the crude enzyme preparation (MTA) containing MP, TP and a saccharogenic amylase from a strain (SH-35) of Plesiomonas in the absence and presence of a starch debranching enzyme, respectively. A stable maltose syrup (70%, w/w) containing about 30% trehalose in the dry solid was prepared from starch directly, and about 36% as dry basis of the mother liquor (70%, w/w) containing about 56% trehalose was obtained as crystals of this non-reducing disaccharide by conventional crystallization. Trehalose in the by-product obtained after removing crystals increased up to almost that of the mother liquor by reacting with MTA again. By the method reported here, trehalose was produced from starch on an industrial scale without any remaining by-products.     

Steady and Dynamic Shear Rheology of Fucoidan‐Buckwheat Starch Mixtures

Rheological properties of fucoidan (F) and buckwheat starch (B) mixtures (3% or 6%) at different blending ratios of fucoidans (0, 0.1, 0.2, 0.5 and 1.0%) were investigated in steady and dynamic shear. Steady shear viscosity measurement revealed that aqueous pastes of the BF blends (3%, w/v) had a pseudoplastic and shear‐thinning behavior with flow behavior index (n) values of 0.61–0.68. The substitution of starch with fucoidan polymers significantly lowered the apparent viscosities compared with the pure starch paste and, when mixed with less than 0.5% of fucoidan, the viscosities of the pastes were even lower than those of the starch pastes at the corresponding starch concentrations. According to dynamic viscoelastic measurement performed at 6% total carbohydrate concentration, buckwheat starch mixtures behaved like weak gels and the BF blends containing less than 0.5% fucoidan had considerably lower storage (G') and loss (G') moduli than the starch paste at the corresponding starch concentrations. However, the magnitude of G' increased with fucoidan concentrations over 0.5%, suggesting that a concentration of fucoidans > 0.5% might enhance the formations of three‐dimensional networks and crosslinking of the starch samples, probably because of the mutual exclusion between starch and fucoidan polymers through the phase separation process. This study indicates that it is possible to obtain the BF blends having various rheological properties by changing the concentration of fucoidan polymers.     

An investigation into the application of konjac glucomannan as a flavor encapsulant

The application of konjac glucomannan (KGM) in flavor encapsulation in the spray-dry method was investigated in this paper using sweet orange oil as the model. KGM provided the highest encapsulation yield when the apparent viscosity of the KGM solution was reduced to 200 mPa S by cellulase hydrolysis. In the presence of emulsifier Tween 80, the hydrolyzed KGM offered comparable encapsulation yield with Arabic gum and starch sodium octenyl succinate (SSOS), but provided significantly higher encapsulation yield than maltodextrin. Besides, the combination of KGM with Arabic gum, SSOS, and maltodextrin, were also studied. The combination could significantly (P < 0.05) increase the encapsulation yield in the KGM content up to 80% compared with pure KGM; when the KGM content was reduced to 20%, the combination with maltodextrin resulted in a significant (P < 0.05) decrease in encapsulation yield, possibly due to the poor emulsifying capability of both KGM and maltodextrin. The effect of encapsulation on flavor composition was investigated by using the fingerprint technique and the vectorial angle method was adopted to assess the similarity between the chromatographs. The comparison showed that KGM had similar flavor retention with SSOS and Arabic gum, but provided a significant (P < 0.05) higher retention than maltodextrin. The encapsulated flavors exhibited few pores and smooth surface under TEM with the size ranging from 5 to 15 μm. It was concluded that KGM provided comparable flavor retention capability as the most widely used Arabic gum and SSOS and had great potential as a flavor encapsulant.     

Changes in the non-structural carbohydrates associated with the field drying of oat forage

Two trials were conducted to determine the sugars, fructans and starch in oat plants (Avena sativa L) and the changes occurring in these carbohydrate fractions during field drying in the haymaking process. The composition of oat herbage in non-structural carbohydrates varied markedly between years; the contents of sugars, fractals and starch in both leaf blade and non-leaf blade materials being nether in 1990–1991 than in 1991–1992. Field drying produced a significant decrease (P < 0.05) in the amount of soluble carbohydrates. For the whole aerial plant parts, the decline in the fructans concentration ranged between 42.8 and 38.2% and that of sugars between 16.5 and 5.8%. The total losses of sugars and fractions in hay, expressed as losses of dry matter, ranged from 88 to 63 g kg^?1 depending on the year.     

Mechanical and Microstructural Properties of “Wet” Alginate and Composite Films Containing Various Carbohydrates

Composite “wet” alginate films were manufactured from alginate–carbohydrate solutions containing 5% alginate and 0.25% pectin, carrageenan (kappa or iota), potato starch (modified or unmodified), gellan gum, or cellulose (extracted or commercial). The “wet” alginate films were used as a model to understand co‐extruded alginate sausage casings that are currently being used by several sausage manufacturers. The mechanical, optical, and microstructural properties of the calcium cross‐linked composite films were explored. In addition, the water holding capacity and textural profile analysis properties of the alginate–carbohydrate gels were studied. The results indicate that the mechanical properties of “wet” alginate films/casings can be modified by adding various carbohydrates to them. Alginate films with pectin, carrageenan, and modified potato starch had significantly (P < 0.05) greater elongation values than pure alginate films. The alginate–pectin films also had greater (P < 0.05) tensile strengths than the pure alginate films. Alginate films with extracted cellulose, commercial cellulose, and modified potato starch had lower (P < 0.05) puncture force, distance, and work values than the alginate control films. Transmission electron microscopy images showed a very uniform alginate network in the control films. Several large cellulose fibers were visible in the films with extracted cellulose, while the cellulose fibers in the films with commercial cellulose were difficult to distinguish. Despite these apparent differences in cellulose fiber length, the 2 cellulose films had similar puncture and tensile properties.     

In vitro starch digestion in sweet potato (Ipomoea batatas L.) flours

The kinetics of starch digestion in cryo‐ and hammer‐milled sweet potato flours were investigated to reveal monophasic digestograms that were independent on particle size (80–390 μm), and suitably described (r² > 0.98; P < 0.05) by a modified first‐order model. Milling conditions significantly affected (P < 0.05) the particle size, salivary–gastric‐digested starch and rate of starch digestion as the effective surface areas changed. The reciprocal of the rate of starch digestion (1/K, s) was significantly related to the square of the average particle size (size², cm²), with the reciprocal of the slope (0.9–3.8 × 10^?7 cm² s^?1) revealing diffusion‐controlled digestion. The hammer‐milled flours gave different digestion and functional parameters as frictional heat and glass transition phenomena played different roles in the overall structural changes in the flours. These parameters are discussed with starch digestion parameters in cereals and legumes to understand starch digestion in sweet potato.     

红小豆-粳米混合食物的碳水化合物体外消化速度研究

碳水化合物的消化速度直接影响着淀粉类主食的餐后血糖反应,因此可利用碳水化合物的体外模拟消化预测淀粉类主食品的血糖反应。用胰酶模拟小肠消化测定了几种烹调方法下红豆-粳米混合膳食中碳水化合物的消化速度,并探讨了其中快速消化淀粉(RDS)、慢速消化淀粉(SDS)和抗性淀粉(RS)相对含量的变化,结果表明:高压烹调显著提高了整豆-粳米混合食物的水解率和RDS含量,但豆粉-米混合食物在不同烹调压力下的差异不显著。整豆和大米分别烹调后再混合的食物与豆谷共同烹调食物相比,抗性淀粉的含量较高,且淀粉消化指数较低。红小豆-粳米混合食物的消化速度与精白粳米的消化速度呈显著性差异(p<0.05)。烹调方法对食物中碳水化合物的消化速度有很大影响。血糖调节异常的人群适合在主食原料中添加整豆类食物,以帮助稳定餐后血糖反应。     

Possible Mechanism of Co‐Flocculation Between Non‐Flocculent Yeasts†

Co‐flocculation between cells of S. cerevisiae NCYC 234 and NCYC 1109, both of which were non‐flocculent when cultivated in YM medium for 20 h, was investigated by chemical modification. Ca²⁺ promoted co‐flocculation. Protein‐denaturants and several carbohydrates caused reversible inhibition of the co‐flocculation in the presence of Ca²⁺. The effect of treatment with proteolytic enzymes and chemical modification of cell surface protein and carbohydrate components suggest strongly that co‐flocculation between cells of NCYC 234 and cells of NCYC 1109 results from interaction between surface protein component of cells of NCYC 1109 and surface carbohydrate component of cells of NCYC 234.