乳熟期鲜食玉米穗不同部位碳水化合物的变化

对乳熟期鲜食玉米穗不同部位碳水化合物的变化研究表明，籽粒中可溶性总糖（TSC）质量分数为先增加后降低，蔗糖（SUC）和TSC的变化趋势相似，淀粉质量分数逐渐增加，可溶性酸性蔗糖转化酶的活性先增加后降低．穗轴中SUC及TSC质量分数在授粉后任何时期总是高于籽粒，淀粉质量分数远低于籽粒．苞皮中TSC与SUC质量分数缓慢减少，在籽粒灌浆初期积累有大量的TSC，为籽粒迅速灌浆做出了贡献，淀粉质量分数远低于穗轴．鲜食玉米采收后应低温放置或及时加工，以抑制糖快速转化为淀粉，防止鲜食玉米品质下降．     

Amylolytic Cultures of Lactobacillus acidophilus : Potential Probiotics to Improve Dietary Starch Utilization

ABSTRACT: The amylase activity of twenty strains of Lactobacillus species isolated from intestinal contents of pigs was studied in vitro. Hydrolysis of starch was measured by following the disappearance of starch in a broth medium during the growth of all three strains. The amount of enzyme activity varied among strains. Three strains (A-4, L9 and L23) were selected for further study based on their high amylolytic activity in a broth containing soluble starch as the only carbohydrate source. Strains A-4 and L23 were identified as L. acidophilus and strain L9 was identified as L. fermentum. Among the three cultures, L. acidophilus L23 was selected as a potential candidate for use as a probiotic for improving digestion of starch in pigs based on its growth and hydrolysis of raw starch. The enzyme activity of L. acidophilus L23 was associated with the cell envelope and that of L. fermentum L9 was extracellular. The enzyme activity of L. acidophilus A4 was found in both locations. The enzyme activity of L. acidophilus L23 was inducible rather than constitutive.     

乳酸菌发酵对燕麦淀粉物化及热力学特性的影响

以燕麦粉为原料,分别利用植物乳杆菌(L.p)和旧金山乳杆菌(L.s)两种乳酸菌对其进行发酵,研究燕麦淀粉在发酵过程中各种物化及热力学特性的变化。结果表明：燕麦粉经过两种菌发酵后pH 值下降,且L.p 发酵的燕麦粉pH 值下降的速率和产酸量都大于L.s。但是到发酵后期,两种乳酸菌发酵的燕麦粉pH 值相近。发酵燕麦淀粉的溶解度和溶胀力都随着温度的升高而增加,在不同温度下,其溶胀力和溶解度在发酵过程中的变化趋势不同,经L.P 发酵的样品的溶胀力低于L.s,但溶解度大于经L.s 发酵的样品。快速黏度分析仪(RVA)和差示扫描量热仪(DSC)分析得到发酵过程中燕麦淀粉的变化：发酵后燕麦淀粉糊化过程中峰值黏度随着发酵时间的延长而降低,糊化起始温度提前,糊化所需时间延长,糊化焓升高,且L.s 发酵样品的糊化焓值高于L.p。发酵后燕麦淀粉的直链淀粉含量在发酵过程中呈上升趋势,L.p 发酵的样品的直链淀粉的含量高于L.s。     

Potato Starch and Flour in Frankfurters: Effect on Chemical and Sensory Properties, and Total Plate Counts

Potato starch and flour were examined as possible constituents in frankfurter formulations. Frankfurters manufactured with 3% potato starch or 1.5% potato starch plus 1.5% potato flour in place of 3% wheat flour normally used as a binder, and stored at 4–5°C for 28 days did not differ significantly in percent shrink, water, protein, fat, ash or salt. Residual nitrite levels decreased during the storage period. Total plate counts reflect residual nitrite levels since the frankfurters (3% starch) with the lowest nitrite concentration also had the greatest number of bacteria (6.4 × 10⁶/g) on day 28. Frankfurters formulated with 1.5% potato starch plus 1.5% potato flour were rated more tender and more juicy than those made with 3% potato starch (P≤0.05 and P≤0.01) and 3% wheat flour (P≤0.01 and P≤0.01), respectively. Fresh potato starch and wheat flour franks did not differ from each other in either characteristic but after one week's storage the potato starch samples were rated more tender (P≤0.05) and more juicy (P≤0.01). Less force was required to shear the frankfurters formulated with 3% potato starch.     

Light exposure during storage preserving soluble sugar and l-ascorbic acid content of minimally processed romaine lettuce (Lactuca sativa L.var. longifolia)

Minimally processed romaine lettuce (MPRL) leaves were stored in light condition (2500 lux) or darkness at 4 °C for 7 d. Light exposure significantly delayed the degradation of chlorophyll and decrease of glucose, reducing sugar, and sucrose content, and thus preserved more total soluble solid (TSS) content at the end of storage in comparison with darkness. While, it did not influenced starch content that progressively decreased over time. The l-ascorbic acid (AA) accumulated in light-stored leaves, but deteriorated in dark-stored leaves during storage. The dehydroascorbic acid (DHA) increased in all leaves stored in both light and dark condition, of which light condition resulted in less DHA than darkness. In addition, the fresh weight loss and dry matter significantly increased and these increases were accelerated by light exposure. Conclusively, light exposure in applied intensity effectively alleviated MPRL quality deterioration by delaying the decreases of pigments, soluble sugar, TSS content and accumulating AA.     

Improving gel formation of rice starch added with cross‐linked resistant starch prepared from rice starch

The gel formation properties of non‐waxy rice starch with cross‐linked resistant starch with phosphate (RS4, 10, 20, and 30% based on rice starch) prepared from three rice varieties with different amylose (AM) content were investigated to increase dietary fiber content, improve gel structure, and reduce the glycemic index of rice products. The AM contents of rice starches were 1.71% in Hanganchal1, 22.47% in Nampyeong, and 33.39% in Goamy. All RS4 showed A‐type crystallinity and their RS levels were 46.91, 54.54, and 66.01%, respectively. The initial pasting temperatures of RS4 added rice starches increased as RS4 contents increased, but peak and breakdown viscosities and enthalpy change (△H) reduced. The RS4 addition improved gel shape and texture properties including hardness, cohesiveness, and gumminess, except the 30% Goamy RS4 added gel. The 20% RS4 addition was appropriate to form rice starch gels. The network structure of RS4 added gel formed more regular and firmer than that of control, because RS4 granules were entrapped within the gel matrix like observed by light microscope and scanning electron microscopy. It is suggested that RS4 not only assist in forming a rigid network structure but also increasing a dietary fiber content.

     

H2 production from algal biomass by a mixed culture of Rhodobium marinum A-501 and Lactobacillus amylovorus

To produce hydrogen from starch accumulated in an algal biomass, we used a mixed culture of the lactic acid bacterium, Lactobacillus amylovorus, and the photosynthetic bacterium, Rhodobium marinum A-501. In this system L. amylovorus, which possesses amylase activity, utilized algal starch for lactic acid production, and R. marinum A-501 produced hydrogen in the presence of light using lactic acid as an electron donor. Algal starch accumulated in the marine green alga Dunaliella tertiolecta, and the freshwater green alga Chlamydomonas reinhardtii, was more suitable for lactic acid fermentation by L. amylovorus than an authentic starch sample. Consequently, the yields of hydrogen obtained from starch contained in D. tertiolecta and C. reinhardtii were 61% and 52%, respectively, in the mixed culture of L. amylovorus and R. marinum A-501. These values were markedly superior to those obtained using a mixed culture of Vibrio fluvialis T-522 and R. marinum A-501 described previously. The yield and production rate of hydrogen by R. marinum A-501 from the lactic acid fermentates were higher than from authentic lactic acid, suggesting that the fermentates contain a factor(s) which promotes H2 production by this bacterium.     

Textural properties of mung bean starch gels prepared from whole seeds

The textural properties of mung bean starch gels (MSG) made by starches purified from whole seeds of Dahyeon were investigated to improve the quality of Korean traditional starch gel, cheongpomuk. Based on our investigation, the protein and dietary fiber contents of starch from whole mung beans (WM) were significantly higher than those from hulled mung beans (HM); however, apparently, WM had lower amylose contents than HM (their respective apparent amylose contents were 32.42 and 33.09%). The fresh gels (WMSG and HMSG), stored gels (WMSG-S4 and HMSG-S4), and reheated gels (WMSG-R4 and HMSG-R4) were also compared. The stored gels showed the highest L and b values, translucence, hardness, and gumminess. While HMSG showed a denser network structure than WMSG, the structure of stored gels was recovered after reheating. The fresh gels showed V type crystallinity, but the stored gel changed into B type crystallinity. WMSG showed higher sensory bending properties and smoothness than HMSG, but more similarities in the overall qualities.     

Effect of Trisodium Citrate Concentration and Soy Cheese on Meltability of Pizza Cheese

The objective of this study was to determine the effect of soy cheese (tofu) and trisodium citrate (TSC) concentration on physicochemical properties of pizza cheese. The results indicated that fat and FDM contents of pizza cheese increased significantly with increased proportion of TSC, while moisture and protein decreased but not significantly (P < 0.05). On the other hand, the fat, FDM, and protein content decreased with increased proportion of tofu, while moisture increased. The melting area and melting degree indicated that melting properties of pizza cheese decreased significantly, as the concentration of TSC increased. Furthermore, increase approximately 5 and 10% tofu in the blends with 0.5% TSC or 10% tofu in the blends with 1% TSC affected notable decrease in melting properties. Among each level of tofu, oiling off area showed significant increase with increasing TSC. Increase in tofu proportion as well as different TSC concentration resulted in decrease in free oil. The control cheese with 1% TSC (CC2C) had maximum oiling off, and with increase in tofu proportion there was a corresponding reduction (P < 0.05) in the oiling off area. It was observed that increase approximately 10% tofu in the blends with 0.5% TSC cause marked reduction in oiling off area by approximately 47%. There was rapid increase in oiling off area during the early stage of cooking. According to observation, free oil formation of cheese with 1% TSC (C2C) was higher than that of the cheese with 0.5% TSC (C1C), especially during 2.5 to 10 min (P > 0.05). Oiling off area of treatments decreased independently of trisodium citrate prolong cooking as the proportion of tofu increased.     

低温和超低温冷冻对糯米淀粉凝胶老化特性的影响

本文研究了糯米淀粉凝胶经过低温（-20、-40℃）和超低温（-195℃）冷冻后在4℃下冷藏过程中对糯米淀粉凝胶老化特性的影响。结果表明,低温和超低温冷冻的糯米淀粉凝胶在冷藏过程中都形成了海绵结构,且超低温冷冻的糯米淀粉凝胶的孔洞小且均匀,形成致密结构;随着冷藏时间的延长,糯米淀粉凝胶的结晶度增大,经过-20、-40、-195℃冷冻后冷藏21 d的淀粉凝胶结晶度分别为6.05%、5.37%和3.83%;糯米淀粉凝胶的老化焓值和硬度值均随着冷藏时间的延长而增大,但随着冷冻温度的降低,糯米淀粉凝胶的老化焓值和硬度值显著降低。由此显示糯米淀粉凝胶经过低温和超低温冷冻处理后,在4℃下冷藏过程中能够有效地抑制淀粉凝胶的老化,并且超低温冷冻处理能显著（p<0.05）的抑制糯米淀粉凝胶的老化。      

Effects of two types of emulsifying salts on the functionality of nonfat pasta filata cheese

Effects of 2 types of emulsifying salts (ES) on the functionality of nonfat pasta filata cheese were examined. Nonfat pasta filata cheese was made from skim milk by direct acidification. Trisodium citrate (TSC) and tetrasodium pyrophosphate (TSPP) were added to curds (at 1, 3, and 5%, wt/wt) at the dry-salting step, together with glucono-δ-lactone to maintain a constant pH. When TSC was added, there were no significant compositional differences, although insoluble Ca and P contents significantly decreased with the addition of TSC. When TSPP was added, fat content was not significantly different, but protein content decreased with increasing concentrations of TSPP. Both insoluble Ca and P contents increased with the addition of 1% TSPP. The addition of ES affected textural and functional properties. With increasing concentrations of TSC, meltability increased, whereas increasing the TSPP content decreased meltability. Cheese made with 1% TSC had better stretchability compared with control cheese. However, the addition of more than 3% TSC decreased stretchability. Addition of TSPP caused a considerable decrease in stretchabilty. Scanning electron microscopy revealed that the size and number of serum pockets decreased and protein appeared more hydrated with the addition of both ES. These results suggested that TSC and TSPP influenced the functionality of nonfat pasta filata cheese differently; that is, the effects of TSC were probably caused by a decrease in the number of colloidal calcium phosphate cross-links and an increase in electrostatic repulsion, whereas the effects of TSPP may have been related to the formation of new TSPP-induced casein-casein interactions.     

Highly fermentable starch at different diet starch concentrations decreased feed intake and milk yield of cows in the early postpartum period

The objective of this study was to evaluate the effects of diet starch concentration and fermentability (SF) fed during the early postpartum (PP) period on dry matter intake (DMI), yields of milk and milk components, body reserves, and metabolism. Fifty-two multiparous Holstein cows were used in a randomized block design with a 2 × 2 factorial arrangement of treatments. Treatment diets were formulated to 22% (LS) or 28% (HS) starch with dry ground corn (DGC) or high-moisture corn (HMC) as the primary starch source. Treatments were fed from 1 to 23 d PP and cows were switched to a common diet until 72 d PP to measure carryover (CO) effects. Treatment period (TP) diets were formulated for 22% forage neutral detergent fiber and 17% crude protein, and starch concentration was adjusted by substitution of corn grain for soyhulls. Throughout the experiment DMI and milk yield were measured daily, and milk components, body condition score (BCS), and body weight were measured weekly. Blood was collected weekly during the TP and every second week during the CO period. During the TP, HMC decreased DMI more when included in the HS (3.9 kg/d) than in the LS (0.9 kg/d) diets and HMC decreased yields of milk, fat, and FCM by 4.3, 0.19, and 4.8 kg/d, respectively. Treatments also interacted over time to decrease DMI and yields of milk and milk components more for HMC compared with DGC as time progressed during the TP. Loss of BCS was increased when HMC was fed in a HS diet (?0.38 vs. ?0.17) and decreased when included in a LS diet (?0.21 vs. ?0.29) with no effects on body weight change during the TP. Treatments interacted with time to affect plasma concentrations of glucose and insulin with HS increasing concentrations early in the TP compared with LS but with similar effects by the end of the TP. During the CO period, treatment effects on DMI diminished over time with no main effects of treatment for the entire period. Starch concentration and SF interacted to affect yields of milk, fat, and FCM during the CO period, which were greater for HS-DGC and LS-HMC (54.8 and 52.8, 1.76 and 1.81, and 51.3 and 52.2 kg/d, respectively) than for LS-DGC and HS-HMC (51.2 and 51.0, 1.68 and 1.64, and 48.4 and 48.6 kg/d, respectively). Treatments did not affect BCS change during the CO period but HS lost body weight compared with LS (?5.7 vs. 7.0 kg). Blood glucose and insulin concentrations were not affected by treatments during the CO period. Feeding a highly fermentable starch source during the early PP period decreased DMI and yields of milk and milk components compared with a less fermentable starch source and the depression in DMI was greater when fed in the higher starch diet. However, diet starch concentration had no effects on yield of milk or milk components.     

The occurrence of Listeria species in milk and dairy products: a national survey in England and Wales

A total of 4172 samples of milk, cheese and other dairy products were examined over a 1-year period for the presence of Listeria species. Strains of Listeria were found most frequently in soft, ripened cows milk cheese; 63 out of 769 (8.2%) samples contained Listeria monocytogenes, 25 samples contained species other than L. monocytogenes, and 18 samples contained both L. monocytogenes and other Listeria spp. Eleven samples of pasteurized cows milk (1.1%) from four dairies contained L. monocytogenes, and other Listeria spp. were isolated from a further five samples. Goats and ewes milk and their products, yogurt, cream and ice cream also occasionally contained Listeria spp. Levels of Listeria were usually low, but 20 samples of cheese contained more than 1000 cfu/g. Most strains of L. monocytogenes belonged to serotype 1/2 (58%) or serotype 4b (33%).     

融合子F3产衣康酸的培养基组成及摇瓶发酵条件的优化

对直接利用生淀粉发酵产衣康酸的融合子F3的发酵条件进行了研究。得到较佳培养基组成及发酵条件为:玉米淀粉110g/L,NH_4NO_3 3.0g/L,玉米浆2.5mL/L,MgSO_4·7H_2O1.5g/L,CuSO_4·5H_2O2.0 mg/L,初始pH3.0～3.5,摇瓶装液量80mL/500 mL三角瓶,接种量10%(种龄44h),34℃振荡(220r/min)培养140h。在此条件下,F3衣康酸产率达到45.3g/L,比优化前提高了4.4g/L;对供给淀粉的转化率达41.2%。     

Metabolic and hormonal control of energy utilization and partitioning from early to mid lactation in Sarda ewes and Saanen goats

In a recent study, we observed that starch-rich diets used in mid lactation induced lower milk production persistency and higher body fat accumulation in dairy ewes compared with dairy goats. Because these species differences could be linked to hormonal mechanisms that drive energy partitioning, in the same experiment, we explored the evolution of metabolic and hormonal status during lactation to test this hypothesis. Twenty mature Sarda dairy ewes and 20 mature Saanen goats [15–134 ± 11 d in milk (DIM), mean ± SD] were compared simultaneously. In early lactation, each species was allocated to one dietary treatment: high-starch diet [HS: 20.4% starch, on dry matter (DM) basis], whereas from 92 ± 11 DIM, each species was allocated to 1 of 2 dietary treatments: HS (20.0% starch, on DM basis) and low-starch (LS: 7.8% starch, on DM basis) diets. Blood samples were collected in the morning to analyze glucose, nonesterified fatty acids (NEFA), growth hormone (GH), insulin, and insulin-like growth factor I (IGF-I). Data were analyzed using the PROC MIXED procedure of SAS with repeated measurements (SAS Version 9.0). The HS and LS diets applied in mid lactation did not affect metabolic status of the animal within species; thus, only a comparison between species was carried out. From early to mid lactation, plasma glucose concentration was higher in ewes than in goats (54.57 vs. 48.35 ± 1.18 mg/dL), whereas plasma NEFA concentration was greater in goats than in ewes (0.31 vs. 0.25 ± 0.03 mmol/L). Goats had higher plasma GH concentration and lower plasma insulin content than ewes (4.78 vs. 1.31 ng/mL ± 0.47; 0.11 vs. 0.26 μg/L ± 0.02). Plasma IGF-I concentration did not vary between species. The comparison of metabolic and hormonal status of lactating Sarda dairy ewes and Saanen goats, carried out by studying simultaneously the 2 species in the same stage of lactation and experimental conditions, suggests that the higher insulin and glucose concentration observed in Sarda ewes explains why they partitioned more energy toward body reserves than to the mammary gland, especially in mid lactation. This can justify the negative effect of high-starch diets in mid-lactating Sarda ewes. Conversely, the highest GH and NEFA concentration observed in Saanen goats explain why they partitioned more energy of starch diets toward the mammary gland than to body reserves and justify the positive effect of high-starch diet in mid lactation. Together, these different responses contribute to explain why specialized dairy goats, such as the Saanen breed, have a higher milk production persistency than specialized dairy sheep breeds, such as the Sarda.     

Microscop of Rice Starch Granules During Cooking

Starch from five cultivars of rice was pasted in the Brabender viscograph and then held at 95°C for 60min. Granules were examined by light and scanning electron microscopy. In concentrated (12%) pastes, low-amylose rice starch showed total granule disintegration after 60min of cooking at 95°C, but highamylose granules showed only marginal disorganization. Waxy starch granules were disintegrated even at 70°C. In dilute (1%) pastes, on the other hand, granules swelled without appreciable disruption, apparently more in low than in high amylose starch. Clearly low amylose starch granules were weak and fragile and so swelled as well disintegrated easily, while high amylose rice starch was relatively strong and rigid and so resisted swelling as well as disintegration. This relative regidity/fragility of starch granules seemed to be the key to differences in rice quality.     

Modified starch granules as particle-stabilizers of oil-in-water emulsions

Oil-in-water (O/W) emulsions of 20 vol% n-tetradecane have been prepared using food-compatible hydrophobic starch particulates as the primary emulsifier. As such, the systems appear to be Pickering emulsions. The starch particulates were generated from chemically cross-linked granules that do not swell on prolonged contact with water and which were made partially hydrophobic by reaction with octenyl succinic anhydride. The degree of substitution was of the order of 0.03. The size of the modified starch particulates was reduced by freezer-milling before preparing the emulsions via a jet homogenizer. Conventional light transmission microscopy, confocal laser scanning microscopy, scanning electron microscopy, multi-angle light scattering and laser Doppler light scattering all suggested that a wide range of starch particle sizes was produced. Some particles were considerably smaller than the original starch granule sizes, but a large proportion appeared to be above several microns in size. The emulsion droplets produced using 1–3 wt.% of starch as emulsifier were quite large (from approximately 1 to 20 μm in diameter), i.e., of the same order of size as a large proportion of the starch particulates. Consequently, the emulsions creamed readily, but they were extremely stable to coalescence with no significant change in the emulsion droplet-size distributions appearing for over 3 months. Further tests on the surface tensions of the homogenized and non-homogenized starch dispersions themselves confirmed the supposition that the O/W emulsions were stabilized by starch particulates and not starch molecules.     

Performance of dairy cows fed diets formulated at 2 starch concentrations with either canola meal or soybean meal as the protein supplement

This study was designed to evaluate the effects of substituting corn grain with nonforage fiber sources in diets containing soybean meal (SBM) or canola meal (CM) as the primary protein source. Sixteen Holstein cows were assigned to a replicated 4 × 4 Latin square design with 4 periods of 28 d each. Treatments were arranged as a 2 × 2 factorial with 2 protein sources (SBM and CM) and 2 dietary starch concentrations (21 and 27% dry matter, DM). Diets were formulated to contain 16.5% CP, and the 21% starch diets were obtained by replacing corn grain with soybean hulls and beet pulp. Protein source × starch interactions were observed for DM intake (DMI), milk fat and protein concentrations, milk protein yield, milk urea nitrogen, and feed efficiency. Cows fed CM diets had a higher DMI when dietary starch concentration was 27% compared with 21%, but those cows had DMI similar to that of cows on SBM diets regardless of the starch concentration. Milk fat percentage was decreased in cows fed CM with 27% starch compared with cows fed CM with 21% starch and cows fed SBM with 27% starch. Milk protein percentage and yield and milk lactose percentage were least in cows fed CM with 21% starch compared with the other 3 diets, but feed efficiency was greater for cows fed CM with 21% starch. Milk urea nitrogen was least in cows fed CM with 27% starch compared with the other 3 diets. Cows fed diets with 27% starch produced 2.5 kg/d more milk and 1.9 kg/d more energy-corrected milk compared with cows fed 21% starch. Digestibility of DM and organic matter was higher in cows fed SBM diets than in cows on CM diets, and cows fed 27% starch showed greater DM and organic matter digestibility than cows on 21% starch. Digestibility of neutral detergent fiber and acid detergent fiber was greater in diets with SBM than in those with CM. Molar proportion of acetate was the lowest for cows fed CM with 21% starch compared with cows fed SBM with 21% starch, with the remaining cows fed being intermediate and similar. However, propionate was highest for cows fed CM with 21% starch than for cows fed SBM with 21% starch, but the remaining treatments were intermediate and similar. Isobutyrate was greater for cows fed CM with 21% starch, which resulted in the lowest acetate:propionate ratio compared with cows fed the remaining treatments. Overall, we confirmed that the interaction of protein with starch in CM diets can sustain similar cow performance as with the SBM diets. Those making decisions about starch concentration and protein source should consider feed price when SBM or CM and different starch levels are being formulated in diets for lactating dairy cows.     

Physicochemical Properties of Oxidized Cassava Starch Prepared under Various Alkalinity Levels

The physicochemical properties of hypochlorite‐oxidized cassava starch as influenced by the alkalinity levels (pH 8 to 11) during modification process were investigated. Hypochlorite oxidation generally increased the contents of carbonyl and carboxyl groups in starch but decreased starch viscosity. The formation of carbonyl and carboxyl groups was more favorable under the milder alkaline conditions (pH 8 and 9). Oxidation conducted at higher alkalinity levels produced both functional groups at a much slower rate and to a lesser extent. Starch viscosity decreased markedly with increasing reaction time. The alkalinity levels during the modification process greatly influenced the initial viscosity of the oxidized starch paste and the viscosity stability of the paste during storage. Thermal behavior studies by differential scanning calorimetry (DSC) demonstrated that oxidation decreased both gelatinization temperature and enthalpy. The decrease in gelatinization temperature was strongly related to the carboxyl group content. The more carboxyl groups the oxidized starch contained, the lower was the gelatinization temperature. Retrogradation of amylopectin tended to increase slightly after oxidation. While the light transmittance of native starch paste drastically decreased during cold storage, the changes observed in oxidized starch pastes were less pronounced and appeared to depend on carboxyl content. The results from light transmittance studies suggested that carboxyl groups introduced into the starch molecules could effectively prevent retrogradation.     

Effect of Asian sea bass bio-calcium on textural,rheological, sensorial properties and nutritive value of Indian mackerel fish spread at different levels of potato starch

Effect of potato starch (2%–4%) and Asian sea bass bone bio-calcium (BC) (0%–10%) on characteristics of Indian mackerel fish spread was investigated. Starch levels had higher impact than bio-calcium concentration on characteristics of fish spread (P < 0.05). Firmness, consistency and cohesiveness of fish spread were raised with increasing starch and BC levels (P < 0.05). Highest lightness (L*) was found in fish spread added with 2% starch and 10% BC (P < 0.05). Highest a*, b*, C*-values but lowest hue angle were obtained in fish spread added with 4% starch and 10% BC (P < 0.05). Higher G' and viscosity were observed in sample added with 4% starch when BC was incorporated at higher level. All fish spreads generally showed shear thinning flow behaviour. Higher acceptability was attained for fish spread containing 4% starch and 10% BC without grittiness. This fish spread showed higher ash with lower moisture, protein and lipid contents than those without BC. Calcium solubility of fish spread was augmented after in vitro gastrointestinal tract system when fortified with 10% BC, and higher solubility of calcium was also noticeable, compared to BC itself. Overall high PUFA, acceptable PV and TBARS value were attained for fish spread fortified with 4% starch and 10% BC.