疣柄魔芋淀粉理化及功能性质研究

为了探索一种新的淀粉资源,对疣柄魔芋淀粉的性质进行了研究。通过电子显微镜、激光粒度分析、X-衍射分析、红外光谱分析等分析手段,并以玉米淀粉和木薯淀粉进为比较,结果显示:疣柄魔芋淀粉淀粉颗粒呈多面体形,棱角较尖锐突出;其粒径小于木薯淀粉和玉米淀粉;结晶型为A-型,相对结晶度为37.4%;红外光谱吸收峰、吸收强度与木薯淀粉和玉米淀粉基本相同;凝胶强度、糊化起始温度和糊化热焓高于木薯淀粉和玉米淀粉;且其抗酶解性优于木薯淀粉和玉米淀粉。因此,疣柄魔芋淀粉是一种潜在的可被开发为抗性淀粉的新资源淀粉。     

Low‐salt restructured fish products using microbial transglutaminase as binding agent

Low‐salt restructured silver carp products were obtained using mechanically deboned fish meat from filleting wastes of silver carp (Hypophthalmichthys molitrix). The additives used were NaCl at three levels (0 (control), 10 and 20 g kg^?1) and microbial transglutaminase (MTGase) also at three levels (0 (control), 3 and 6 g kg^?1). The fish meat was massaged with the additives at <15 °C for 1 h. The massaged fish paste was then packed into steel stainless tubes and cooked at 40 °C for 30 min followed by 90 °C for 15 min. Changes in mechanical properties (texture profile analysis and punch test), solubility, electrophoretic profile and expressible water were evaluated. Hardness was in the range from 26.3 to 52.4 N, cohesiveness varied from 0.185 to 0.318 and springiness varied from 0.418 to 0.768. Increasing the amount of both additives improved the mechanical and functional properties of the restructured silver carp products. MTGase activity was associated with a decrease in protein solubility and a decrease in the myosin band (SDS‐PAGE). Increasing NaCl decreased the amount of expressible water. The results indicated that it is feasible to obtain low‐salt restructured silver carp products with improved mechanical and good functional properties using 3 g kg^?1 MTGase and 10 g kg^?1 NaCl. © 2002 Society of Chemical Industry     

Effect of mixed kojis on physiochemical and sensory properties of rapid‐fermented fish sauce made with freshwater fish by‐products

The objective of this study was to investigate the effect of mixed kojis on essential indices of fish sauce. Fish sauce inoculated with mixed kojis (FSB, Aspergillus oryzae koji:Aspergillus niger koji = 3:1) and A. oryzae koji (FSA, control) was prepared. At the end of fermentation, the content of amino nitrogen, total soluble nitrogen, Free amino acid (FAA) and glutamic acid in FSB increased by 7.50%, 7.84%, 9.80% and 28.43% compared to FSA, due to higher acid protease activity in mixed kojis. Moreover, flavour groups including phenols, ketones and nitrogen‐containing compounds in FSB were also improved. According to the results of sensory evaluation, FSB showed higher intensity of umami and caramel attributes, lower intensity of ammonia and sour attributes. All the results suggested that the usage of mixed kojis to produce fish sauce was an effective method that can accelerate the fermentation process and improve the flavour of fish sauce made with freshwater fish by‐products.     

Dependence of physiochemical,functional and textural properties of high‐resistant starch rice on endogenous nonstarch polysaccharides

To investigate the possibility of improving the quality of rice rich in resistant starch through operation of nonstarch polysaccharides, the high dietary fibre (7.24%) mutant cw and its wild‐type R7954 were selected to study the physiochemical characteristics of starch before and after removal of nonstarch polysaccharides. Results showed that hydrolysed or partially hydrolysed nonstarch polysaccharides in cw decreased the resistant starch content significantly, from 15.23% to 10.8%. Nonstarch polysaccharides had significant influences on the gelatinisation temperature, RVA parameters of R7954, but no significant influences on that of cw. For cw, removal of cellulose increased swelling power and adhesiveness, decreased the hardness significantly, from 0.3 to 0.23 N, while the resistant starch content was still as high as 13.72% and showed no significant difference from the wild type. This suggests that the influences of nonstarch polysaccharides on starch properties depend both on the type of rice and the nonstarch polysaccharides. Operation on nonstarch polysaccharides for obtaining rice with lower glycemic index is feasible, but operation on nonstarch polysaccharides may also be an alternative way of improving the palatability for rice high in resistant starch.     

Preparation and structural properties of small‐particle cassava starch

Acid and enzyme hydrolyses followed by ball milling were applied to fracture cassava starch granules. Microscopic and chromatographic evidence suggested different mechanisms of the two hydrolyses. Using the enzyme process, granules with a sponge‐like structure and shells with the interior hydrolysed were produced. Amylose and amylopectin were subjected equally to multiple attacks by enzymes, with no significant change in granule crystallinity. The hydrolysed residues could not be effectively broken down by ball milling, although the crystallinity was destroyed. In contrast, the acid treatment caused superficial external corrosion, mainly at the amorphous lamellae, ie the branch points of amylopectin. Acid‐lintnerised starch granules were mostly of Degree of polymerization, DP 10–15 and exhibited increased crystallinity and brittleness, making them more susceptible to breakdown upon milling. Ball milling, although destroying some degree of crystallinity, could effectively reduce the size of acid‐hydrolysed starch, with no further degradation of amylodextrin molecules. By a combination of lintnerisation and ball milling, smaller particle starch (3–8 µm compared with 3–30 µm for native starch) could be produced. It is clear that removal of the amorphous phase prior to milling is critical for effective rupture of the granules. Copyright © 2003 Society of Chemical Industry     

Enrichment of fresh pasta with antioxidant extracts obtained from artichoke canning by‐products by ultrasound‐assisted technology and quality characterisation of the end product

This work is aimed at: (i) analysing the extracts obtained from canning by‐products of three artichoke cultivars (Opal, Capriccio and Catanese) for antioxidant parameters; (ii) comparing UHPLC‐ESI‐MS/MS profile, colour, textural properties and cooking performance of fresh pasta enriched of the most antioxidant extract, with control pasta. The concentrated Catanese cv. extracts showed the highest antioxidant activity (1662 μmol Trolox equivalents L^?1) and the highest levels of luteolin‐7‐O‐rutinoside, luteolin‐7‐O‐glucoside and apigenin‐7‐O‐rutinoside compared to other cultivars. Fresh pasta enriched of Catanese extract showed higher (P < 0.05) phenolic compounds and antioxidant activity (500 mg gallic acid kg^?1 and 1324 μmol Trolox kg^?1, respectively) than control pasta (306 mg gallic acid kg^?1 and 886 μmol Trolox kg^?1, respectively). The extract increased (P < 0.05) pasta brownness (from 19.93 to 23.34), and decreased yellowness (from 27.11 to 23.09), but did not alter textural and cooking parameters. So, pasta was a good vehicle to increase the antioxidant dietary intake.     

Effect of acid treatments and drying processes on physico-chemical and functional properties of cassava starch

The effects of acid treatments (HCl or organic acids) and drying processes (oven or sun) on the physico-chemical and functional properties of cassava starch have been studied. The objective was to obtain modified starches with expansion properties similar to those of sun dried fermented cassava starch (polvilho azedo) as produced by an empirical process. Expansion was evaluated using a baking test. Independent of the drying method, organic acid-hydrolysed cassava starch presented the same X-ray diffraction patterns (changes from C to A) and similar intrinsic viscosity values. SEM observations showed no differences between granule surfaces of sun dried and oven dried samples. However sun dried organic acid-hydrolysed starches presented lower paste consistency values at 30°C when compared with oven dried ones. HCl-modified cassava starches were oven or sun dried, giving biscuits with low specific volumes (2·5–3·1 ml g⁻¹). Similar behaviour was obtained using oven dried organic acid modified cassava starches. When submitted to sun drying, organic acid modified starches showed great improvements in biscuit expansion (5–10 ml g⁻¹). The highest average specific volumes were obtained using lactic acid modified starches. © 1998 SCI.     

Stability,sensory quality,texture properties and nutritional value of fish oil‐enriched spreadable fat

A Correction has been published for this article in Journal of the Science of Food and Agriculture 84(15):2142 (2004). The intake of omega‐3 long‐chain polyunsaturated fatty acids (PUFAs) in the typical Western diet is usually below the recommended level. Without radical changes of eating patterns the diet may be enhanced by enrichment of foods with unhydrogenated fish oil, which is the richest source of the long‐chain omega‐3s, eicosapentaenoicacid (EPA) and docosahexaenoicacid (DHA). The aims of the study were to establish the sensorily acceptable fish oil enrichment level of a reduced‐fat spread, to enhance the omega‐3 long‐chain PUFA content and to evaluate the enriched spread's stability during 3 months of storage (6°C, limited exposure to light and air). Samples were prepared in an industrial pilot plant. Overall sensory quality, intensity of fishy flavour, texture properties (sensory and instrumental), peroxide value, acid number and fatty acids composition were measured. A spread enriched by addition of 30.0 g kg^?1 of unhydrogenated fish oil could be stored for up to 3 months without significant decrease of the measured stability indicators. A daily portion of this enriched spread (30 g) would provide 0.25 g of EPA and DHA, significantly increasing long‐chain omega‐3 levels in the average diet. Copyright © 2004 Society of Chemical Industry     

Hydration and physicochemical properties of small‐particle cassava starch

Acid hydrolysis followed by ball milling was applied to cassava starch in order to fracture the granules. Lintnerisation led to degradation first in the amorphous domains and increased the crystallinity. The resulting increase in internal defects and brittleness made the granules more susceptible to breakage upon milling. Ball milling, although leading to some degree of crystallinity loss, could effectively reduce the size of acid‐hydrolysed starch while the total double helix remained relatively unchanged. The resulting small‐particle starch was structurally more heterogeneous (wider T_m range). Swelling of small‐particle starch was accompanied by solubilisation of water‐soluble fragments at a temperature greater than 60 °C. The properties of individual granules are strongly influenced by the hydration and physicochemical properties of their amorphous and crystalline domains. © 2002 Society of Chemical Industry     

Influence of degree of hydrolysis on functional properties and angiotensin I‐converting enzyme‐inhibitory activity of protein hydrolysates from cuttlefish (Sepia officinalis) by‐products

BACKGROUND: In Tunisia the cuttlefish‐processing industry generates large amounts of solid wastes. These wastes, which may represent 35% of the original material and constitute an important source of proteins, are discarded without any attempt at recovery. This paper describes some functional properties and the angiotensin I‐converting enzyme (ACE)‐inhibitory activity of protein hydrolysates prepared by hydrolysis of cuttlefish (Sepia officinalis) by‐products with crude enzyme extract from Bacillus licheniformis NH1. RESULTS: Cuttlefish by‐product protein hydrolysates (CPHs) with different degrees of hydrolysis (DH 5, 10 and 13.5%) were prepared. All CPHs contained 750–790 g kg^?1 proteins. Solubility, emulsifying capacity and water‐holding capacity increased while fat absorption and foaming capacity decreased with increasing DH. All hydrolysates showed greater fat absorption than the water‐soluble fraction from undigested cuttlefish by‐product proteins and casein. CPHs were also analysed for their ACE‐inhibitory activity. CPH3 (DH 13.5%) displayed the highest ACE inhibition (79%), with an IC₅₀ value of 1 mg mL^?1. CONCLUSION: Hydrolysis of cuttlefish by‐product proteins with alkaline proteases from B. licheniformis resulted in a product with excellent solubility over a wide pH range and high ACE‐inhibitory activity. This study suggests that CPHs could be utilised to develop functional foods for prevention of hypertension. Copyright © 2010 Society of Chemical Industry     

Functional and antioxidative properties of protein hydrolysates from Cape hake by‐products prepared by three different methodologies

BACKGROUND: The production of fish protein hydrolysates (FPH) is a convenient technology for upgrading fish by‐products. The aim of this work was to study three different methods of FPH preparation from Cape hake by‐products to improve yield and quality. Functional and antioxidative properties of all FPHs were determined. RESULTS: The protein content of hake FPH was in the range 807–860 g kg^?1 and the degree of hydrolysis was between 19% and 22%. The maximum yield (71.9%) was achieved by methodology B but the hydrolysate was darker. The peptide profile of all FPHs was very similar. FPH prepared by methodology C had significantly higher emulsifying activity index and hydrolysate prepared by methodology B had the highest foaming capacity. The solubility of FPH was in the range 71–76% and increased the water‐holding capacity of minced fish by about 9%. The fractionation of FPH obtained by methodologies A and B allowed concentrating peptides with higher radical scavenging activity and reducing power. CONCLUSION: The properties of the FPH prepared indicated that they can be used in food systems as natural additives, particularly to improve their water‐holding capacity. © 2012 Society of Chemical Industry     

Characterisation of chickpea flour‐based gluten‐free batters and muffins with added biopolymers: rheological,physical and sensory properties

Chickpea flour (CF)‐based muffin formulations were made with CF alone and with added biopolymers [whey protein (WP), xanthan gum (XG) and inulin (INL)] to evaluate their suitability to be a wheat flour (WF) substitute in muffins. Structural characteristics of the batters and muffins were studied by means of rheometry, microscopy, physicochemical properties, and texture and sensory analysis. Partial replacement of CF with XG, alone (at 0.5 and 1%) or blended with either WP or INL, significantly increased the batter viscoelasticity as denser matrices developed; moreover, the muffins with XG added at 1% had similar hardness to wheat gluten muffins. The replacement of WF decreased the springiness, cohesiveness, chewiness, resilience and specific volume of the muffin. However, baked muffins with added XG also showed higher sensory sponginess and moisture associated with numerous air bubbles in the batter and were perceived to be easier to swallow and to have better general appearance.     

Food hydrocolloids as additives to improve the mechanical and functional properties of fish products: A review

The restructuring process offers to fish processors the opportunity to obtain new products, taking advantage of both low-value fish species and remains from filleting and other processing operations. However, mechanical and functional properties of restructured products depend on the biochemical and physicochemical properties of muscle proteins, mainly myosin and actomyosin. In this regard, the biochemistry of fish muscle is different from that of mammals and birds. Therefore, fish products must be processed in a different way from red meat or poultry. The main fish products are surimi and restructured products. Fish products can be improved or modified by using hydrocolloids (carbohydrates and protein) as additives. In this review, the modern technology to obtain these products, the applications of hydrocolloids in fish products, and the implications of the increasing demand for healthy, low-salt fish products are discussed.     

Amaranth flour,cassava starch and cassava bagasse in the production of gluten‐free pasta: technological and sensory aspects

The objective of the present research was to analyse the combined effect of pregelatinised cassava starch and bagasse (70:30) flour, cassava starch and amaranth flour on the cooking properties of pasta, verify the acceptance and buying intention of the product with the best technological characteristics, and finally compare them with commercial products made with regular and whole wheat flour. The vermicelli‐type pasta obtained in this study in the proportion of 10:60:30 (pre‐gelatinised flour:cassava starch:amaranth flour) showed the best results in the quality tests, with a cooking time of 3 min, mass increase of 101.5% and 0.6% solids loss to the cooking water, superior to the commercial pasta. Acceptance testing showed that this was a very good pasta (score of 7.2 on a 9‐point scale) and obtained 42% buying intention amongst the consumers. The elaboration of pasta containing pregelatinised cassava starch and bagasse (70:30) flour, cassava starch and amaranth flour was shown to be a feasible alternative with respect to the technological and sensory aspects, and could be consumed by those suffering from gluten intolerance.     

Morphological,thermal, rheological and noodle‐making properties of potato and corn starch

A comparison between the morphological, thermal, rheological and noodle‐making properties of corn starch and potato starches separated from five different potato cultivars was made. The granule size and shape of all starches differed significantly. Potato starch granules were comparatively larger than corn starch granules, while the transition temperatures were found to be higher for corn starch. Consistency coefficients and flow behaviour indices measured by back extrusion were higher for potato starches than for corn starch. Stickiness of cooked starch pastes was observed to depend upon their consistency coefficient. The gels made from all potato starches showed higher gel strength than those from corn starch. The gel strength of starches from both corn and potato increased during refrigerated storage. The amylose content, swelling power, solubility and light transmittance values of potato starches were significantly higher than those of corn starch. Noodles made from potato starches had higher cooked weight and cooking loss than corn starch noodles. Texture profile analysis revealed that potato starch noodles also had higher hardness and cohesiveness than corn starch noodles. Hardness of cooked noodles from all starches increased and cohesiveness decreased during storage. Noodles made from starches of higher viscosity exhibited higher hardness and cohesiveness. Textural differences among cooked starch noodles appeared to be associated with morphological, thermal and rheological properties of corn starch and potato starches. © 2002 Society of Chemical Industry     

Cassava varietal screening for cooking quality: Relationship between dry matter,starch content,mealiness and certain microscopic observations of the raw and cooked tuber

Thirteen cassava (Manihot esculenta L Crantz) varieties from three successive annual harvests were screened for the mealiness of the cooked tuber, and the elasticity and smoothness of the pounded paste. Six were selected for further studies based on their mealiness and the starch and dry matter contents were determined. The diameter of the starch granules of the selected varieties and those of an irradiated M₁ V₂ population were measured. Microscopic examinations of the raw and cooked cells of the irradiated M₁ V₂ population were made. Correlations among all the parameters were studied. Varietal and seasonal differences in cooking quality were observed. There was no consistent relationship between mealiness of the boiled tuber and the elasticity and smoothness of the pounded paste. Varieties that were mealy were high in dry matter and starch content. The starch granules of mealy varieties were larger than those of nonmealy ones. There were no differences between mealy and non-mealy varieties in the arrangement of the cells or ‘cell condition’, of the raw tubers. However, the cells of the cooked tubers were held less cohesively, ie there was more ‘cell disorganisation’, in mealy varieties than in non-mealy ones.