Rice Protein Concentrate Research Articles

Enzymatic and Histological Evaluations of Gut and Liver in Rainbow Trout, Oncorhynchus mykiss, Fed with Rice Protein Concentrate‐based Diets

This study was carried out in order to investigate the histological and biochemical responses in the gastrointestinal tract (GIT) of rainbow trout fed a rice protein concentrate (RPC). A stock of 360 juvenile rainbow trout (62.4 ± 0.3 g) were randomly distributed into 12 fiberglass tanks and fed with four experimental diets obtained by including graded levels of RPC (RPC: 0, 20, 35, and 53%) replacing fish meal on dry weight basis. The experimental plan was balanced and monofactorial, with four treatments and three replicates. At the end of the experiment, 15 fish per treatment were killed, and different tissues were sampled for biochemical and histological analyses. The results showed that total alkaline proteases were unaffected by RPC inclusion level. Amylase and lipase activities showed slight differences between the groups for all examined tracts. No histopathological changes were observed in GIT for any of the dietary treatments. Liver samples of fish fed with RPC‐based diets were characterized by a slight decrease in lipid vacuolizations and a decreasing trend in the Ceroid Substances Presence Index. In conclusion, RPC did not show detrimental effects on the intestinal morphology and modification of tissue enzyme activity in rainbow trout.

Interfacial and emulsifying behaviour of rice protein concentrate

Interfacial and emulsifying properties of rice protein concentrate (RPC) have been studied in order to evaluate its potential application to stabilize O–W emulsions. The interfacial behaviour of adsorbed proteins films constituted with RPC has been studied at the air–water and oil–water interfaces at two pH values (2 and 8). The type and the amount of soluble proteins have been determined in aqueous dispersions and results put forward the presence of most frequent rice protein profile and a significant degree of protein denaturation with a very low solubility. Air–water and oil–water interfacial properties have been determined as a function of time, concentration and pH: air–water by surface pressure under compression–expansion cycles and oil–water by interfacial tension. Interfacial rheology has been studied under dilatational deformations, either at the initial step of film formation or once the interfacial tension was at equilibrium (the film was completely formed). RPC-stabilised O–W emulsions has been also analysed by Droplet Size Distribution (DSD) measurements and interfacial protein concentration. Both interfacial and bulk emulsion properties reveal that RPC showed an enhanced potential as emulsifier at low pH. Globally; results indicate clearly important differences in the structural characteristics of rice protein films between pH 2 and 8 that impact on emulsifying properties.

Growth and apparent digestibility of nutrients, fatty acids and amino acids in Pacific white shrimp, Litopenaeus vannamei, fed diets with rice protein concentrate as total and partial replacement of fish meal

Growth and apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein (CP), crude lipid (CL), gross energy (GE), essential amino acids (EAA), nonessential amino acids (NEAA) and fatty acids (FA) were determined for the Pacific white shrimp, Litopenaeus vannamei. Five isonitrogenous (36.6% protein) diets, formulated by replacing 0, 25, 50, 75, and 100% of fish meal (FM) with rice protein concentrate (RPC), were fed to shrimp (initial weight 6.99±0.08g) five times daily to satiation for 60days. ADCs were determined using 0.5% Cr2O3. Feces were collected from three replicate groups of shrimp. Shrimp fed with 0, 25 and 50% replacements had similar weight increase (P<0.05), specific growth rate (SGR) and feed conversion ratio (FCR), whereas all the above parameters declined significantly (P<0.05) as the dietary RPC levels increased above 50%. Survival was high (≥95%) and similar for all diets. ADCs of diets were: CP (52.41–90.52%), CL (80.03–94.11%), GE (55.24–89.41%), EAA (57.39–96.13%), NEAA (41.11–94.74%), SFA (24.61–65.43%), MUFA (41.50–80.45%), and PUFA (57.14–83.90%). Generally, a decreasing trend in ADC for crude protein, crude lipid, gross energy and amino acid (AA) was observed when the RPC level increased. ADC of the FA in shrimp fed with FM and 50% RPC were significantly higher than 25, 75 and 100%. The highest digestibility values were obtained in the FM diet (P<0.05). The results suggest that RPC can be a potential candidate for FM replacement up to 50%; reduced growth performance was mostly a consequence of reduced digestible nutrients as the RPC level was increased in the diet.

Replacement of fishmeal with rice protein concentrate in practical diets for European sea bassDicentrarchus labraxreared at winter temperatures

As no information is available regarding the efficacy of using rice protein concentrate (RPC) to replace fishmeal (FM) in diets for European sea bass (Dicentrarchus labrax), a trial was conducted to determine the optimum inclusion for European sea bass juveniles. Diets were formulated to replace 25%, 50% and 75% of fishmeal with RPC. Additional high level inclusion diets (50% and 75%) were supplemented with lysine and methionine to determine if these were limiting factors. Fish (18.0 ± 0.06 g) were fed the experimental diets for 12 weeks. The final mean weight and specific growth rate (SGR) were significantly higher in fish fed the control diet (diet FM) and low level RPC (diet RPC25) than in fish fed the other diets. The supplementation of the amino acids had a positive effect on growth, elevating the final weight of the high level RPC (RPC75 + AA) group above that of the non-supplemented group (RPC75). However, this was still not comparable to fish fed FM and RPC25 diets. No significant differences in body composition were observed. A digestibility study demonstrated an inverse relationship between elevating inclusion levels of RPC and apparent digestibility coefficients (ADCs) for dry matter and lipid, with significantly lower values than the control being observed with RPC inclusions above 25%. The mesenteric fat index followed this trend. Circulating leucocyte levels, leucocyte ratios and serum lysozyme activity remained unaffected by dietary treatment. However, compared with the control group, fish fed RPC75, RPC50 + AA RPC75 + AA displayed significantly lower haematocrit values. The present study demonstrates that the inclusion of RPC at 140 g kg−1 (effectively replacing 25% of FM content) does not compromise European sea bass growth performance, body quality or basic haematological parameters. It is suggested that future studies including higher levels test the efficacy of additional amino acid supplementation (e.g. tryptophan).

Fish meal replacement with rice protein concentrate in a practical diet for the Pacific white shrimp, Litopenaeus vannamei Boone, 1931

Replacement of fish meal (FM) with rice protein concentrate (RPC) as a practical diet for the Pacific white shrimp, Litopenaeus vannamei, was evaluated. Five isonitrogenous (36.6% protein) diets, formulated by replacing 0, 25, 50, 75, and 100% of FM by RPC, were fed to shrimp (initial weight of 6.99 ± 0.08 g) five times daily to satiation for 60 days. Relatively high final weight (FW 17.64–18.25 g) and weight gain (WG 10.81–11.39 g) were obtained in treatments up to 50% of the plant protein inclusion. Above this inclusion level, FW (14.93–14.35 g) and WG (7.68–7.23 g) were reduced. Survival was high (≥95%) and similar for all diets. There were no significant differences (P > 0.05) in tail-muscle composition (moisture, protein, lipid, and ash) among different dietary treatments. Dispensable and indispensable amino acids of the tail muscle of shrimp fed with 25, 50, and 75% RPC were significantly higher than the FM (0%) and 100% RPC diets. A decreasing trend in apparent digestibility coefficient (excluding dry matter) for crude protein (90.52–52.41), ether extract (94.11–80.03), organic matter (87.25–50.16), and gross energy (89.41–55.24) was observed at higher RPC inclusion rates. The results suggest that RPC meal can be a potential candidate for FM replacement up to 50% of the protein in shrimp diets.

Alternative Dietary Sources in Feeding of Blackspot Sea Bream Pagellus bogaraveo (Brunnich, 1768)

The present review reports the results of two studies carried out at the Institute for the Coastal Marine Environment of Messina (Italy) on the suitability of plant-derived raw materials as dietary components for an innovative fish species for aquaculture, black spot sea bream Pagellus bogaraveo. The research focused on the effects of the use of plant (protein/lipid) dietary sources on growth performance, body composition and gastro-intestinal enzyme patterns in nutrient digestion of wild juveniles of P. bogaraveo. In particular, the effect of a total replacement of Fish oil by Echium and linseed oils and a partial substitution of fish meal with a graded level of Rice Protein Concentrate, will be discussed.

Effect of high-level fish meal replacement by pea and rice concentrate protein on growth, nutrient utilization and fillet quality in gilthead seabream ( Sparus aurata, L.)

Partial replacement of fish meal by a vegetable mixture (Pea Protein Concentrate (PPC) and Rice Protein Concentrate (RPC)) was carried out in on-growing gilthead seabream (initial average weight 174 g). The experimental diets were isoproteic (48% CP) and isolipidic (18%) with 0, 30, 60 and 90% of fish meal substitution, supplemented with Methionine and Lysine. Fish were distributed in 12 tanks with 20 fish per tank. At the end of the trial (80 days), fish survival was 90% and there were no differences in growth parameters except for fish fed the 90% (326 g and SGR: 0.78% day − 1 ) diet. No significant differences were found in feed intake ratio (FI), which was around 1.70 to 1.96 g 100 g fish − 1 day − 1 , feed conversion ratio, around 1.9 to 2.4 and protein efficiency ratio, which ranged from 0.96 to 1.2. No statistical differences were observed in biometric parameters. In the retention of amino acids ingested there were no statistical differences among diets, although fish fed the 60 diet obtained the highest values in all EAA compared with other diets. In both ingested and digested amino acids, a higher retention of His and lower retention of Met was observed. Regarding sensory analysis, there were no statistical differences in triangular test for fish fed the various diets.

Rice protein‐concentrate meal as a potential dietary ingredient in practical diets for blackspot seabream Pagellus bogaraveo: a histological and enzymatic investigation

Field and laboratory studies were conducted to evaluate the intestinal responses to partial replacement of fish meal with rice protein concentrate (RPC) in practical diets for blackspot seabream Pagellus bogaraveo. Two experimental diets were formulated to be isoproteic and isoenergetic with an increasing level of RPC (20 and 35%, respectively) and were tested against a fish meal-based control diet (RPC0). The diets showed similar features for growth performances and both intestinal histology and digestive enzymes. This study confirmed that RPC does not induce intestinal mucosa alterations in this fish. The dietary RPC supplement caused a significant increase in trypsin activity, whereas lipase activity was reduced.

Effects of Using Wheat Gluten and Rice Protein Concentrate in Dairy Calf Milk Replacers

ABSTRACT There is a limited amount of peer reviewed data on feeding milk replacers (MR) containing either hydrolyzed wheat gluten (HWG; 80% CP) or rice protein concentrate (RPC; 80% CP) to calves under 2 mo of age. Male Holstein calves less than 7 d old from multiple farms (trial 1) and 2- to 3-d-old calves from one dairy farm (trials 2 and 3) were used. Trial 1 compared feeding 0.454 kg/d of 20% CP, 20% fat MR powders that contained 0 and 4.3% HWG for 42 d. Trial 2 compared feeding 0.681 kg/d of 26% CP, 17% fat MR powders that contained 0, 6, and 12% HWG for 42 d. Trial 3 compared feeding 0.681 kg/d of 26% CP, 17% fat MR that contained 0, 8, and 16% RPC for 28 d. Within trial, the MR were formulated to have equal concentrations of major nutrients and be adequate in essential amino acids. In trial 1, preweaning ADG, starter intake, feed efficiency, and hip width changes were greater in calves fed the MR with 0 vs. 4.3% HWG. In trial 2, preweaning ADG, starter intake, and hip width change decreased linearly with increasing concentration of HWG in the MR. In trial 3, ADG and feed efficiency declined linearly as RPC increased in the MR. In these 3 trials, preweaning ADG of calves less than 2 mo old was reduced when either HWG or RPC replaced whey protein in a MR.

Rice protein concentrate partially replaces dried whey in the diet for early‐weaned piglets and improves their growth performance

AbstractBACKGROUND: Recently, rice protein concentrate (RPC), a much cheaper source of dietary protein, has become commercially available for use in the feed industry. Importantly, dietary supplementation with RPC can increase feed intake by early‐weaned pigs. The objective of this study was to determine whether RPC can replace milk protein in the diet for early‐weaned pigs.RESULTS: Neither average daily gain (ADG), average daily feed intake (ADFI), nor the feed/gain ratio differed among the treatment groups in weeks 1 and 2. In week 3, the addition of 5 or 10% RPC to diets increased (P &lt; 0.05) ADFI and ADG of pigs compared to those in the control group fed a 60% dried whey diet. During the entire 21‐day trial, ADFI and ADG were greater (P &lt; 0.05) in pigs fed the 5 and 10% RCP diets than in pigs fed the 60% dried whey and 15% RCP diets. There were no differences in the serum concentrations of growth hormone on days 14 and 21, serum concentrations of insulin growth factor‐I (IGF‐I) on day 14, or IGF‐I gene expression in liver and skeletal muscle on days 14 and 21 among the dietary treatments. Serum concentrations of IGF‐I in pigs fed the 5, 10 and 15% RPC diets were greater than those in pigs fed the 60% dried whey diet.CONCLUSION: Findings indicate that up to 10% RPC can be used to replace dried whey in the diet for 7‐ to 21‐day‐old weaned piglets and can improve their growth performance. Copyright © 2008 Society of Chemical Industry

Rice protein concentrate meal as a potential ingredient in practical diets for rainbow trout ( Oncorhynchus mykiss)

Rice protein concentrate (RPC) is a good raw material for fish nutrition due to its high protein and lipid content. The aim of this research was to evaluate this source of nutrients as a potential substitute for fish meal in rainbow trout diets. The RPC was characterized on the basis of proximate analyses, fatty acid (FA) profile and amino acid composition and then three experimental diets were formulated to be isoproteic (CP 47%) and isoenergetic (22 MJ kg − 1 DM) with increasing levels of RPC (20%, 35% and 53%) tested against a control diet without RPC (RPC0). An in vivo digestibility experiment was performed in order to determine the apparent digestibility coefficients (ADC s) of the diets using the indirect acid-insoluble ash (AIA) method. Statistical differences appeared among all the diets as far as the dry matter, organic matter, crude protein and gross energy ADC are concerned with a decrease as the RPC level increase. No differences appeared for the ether extract ADC, but a decreasing trend was observed when the RPC level increased. Successively, a feeding trial was performed on triplicate groups of 30 fish (mean weight: 62.4 g) fed experimental diets for 94 days. At the end of the trial, the growth performance traits were determined and somatic indexes were calculated on five fish per each replicate. The diets and dorsal muscles were analysed for the proximate composition, gross energy and FA profile. The main results of the present experimentation are that the FA composition of the fillets did not show any difference between the control group and the fish fed with the RPC diets. Moreover, RPC can be used at an inclusion level of up to 20% without a growth performance reduction in rainbow trout feedstuffs, leading to a saving on fish meal protein. Inclusion of higher levels than 20% resulted in an almost linear reduction in the ADCs of the nutrients and energy and this was mirrored in the growth performance of the fish. Although the level of lysine was marginally limiting in the RPC53 diet, the EAA profile of RPC seems quite good, relative to trout requirements, and there was no major adverse effect of RPC on feed palatability; hence, reduced growth performance was mostly a consequence of reduced digestible nutrient and energy intakes as the RPC level was increased in the diet.

Comparative Efficacy of Plant and Animal Protein Sources on the Growth Performance, Nutrient Digestibility, Morphology and Caecal Microbiology of Early-weaned Pigs

The present study was conducted to evaluate and compare the effects of various animal and plant protein sources on piglet's performance, digestibility of amino acids and gut morphology in weaned pigs until 28 days after weaning. The plant protein sources used were soybean meal (SBM), fermented soy protein (FSP), rice protein concentrate (RPC); and animal protein sources tested were, whey protein concentrate (WPC) and fishmeal (FM). Iso-proteinous (21%) diets were formulated and lysine (1.55%) content was similar in all the diets. The level of each protein source added was 6% by replacing SBM to the same extent from the control diet containing 15% SBM. The ADG was higher (p<0.05) in the groups fed animal proteins as compared with plant proteins at all the levels of measurement, except during 15-28 days. The highest ADG was noted in WPC and FM fed diets and lowest in SBM fed diet. The feed intake was higher in animal protein fed groups than plant proteins at all phases, but the feed:gain ratio was not affected by protein sources except during overall (0 to 14 day) measurement which was improved (p<0.05) in animal protein fed diets compared to plant protein sources. The digestibilities of gross energy, dry matter and crude protein were higher in animal protein fed groups than for plant protein fed sources. The apparent ileal digestibilities of essential amino acids like Leu, Thr, and Met were significantly (p<0.05) higher in animal proteins fed animals as compared with plant protein fed animals. But the apparent fecal digestibilities of essential amino acids like Arg and Ile were significantly higher (p<0.05) in plant protein diets than animal protein sources. The villous structure studied by scanning electron microscope were prominent, straight finger-like, although shortened and densely located in FM fed group as compared with others. The lactic acid bacteria and C. perfringens counts were higher in caecal contents of pigs fed plant proteins than the animal proteins. Overall, it could be concluded that animal protein sources in the present study showed better effects on growth performance, nutrient digestibility and gut morphology than plant protein sources. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 9 : 1285-1293)

Effects of Feeding Rice Protein Concentrate on Growth Performance and Ileal Digestibility in Early-weaned Pigs

These experiments were conducted to evaluate the feeding value of rice protein concentrate (RPC) in weaning pigs. In expt. I, a 5-week feeding trial was conducted with 126 pigs (L×Y×D; 21 d-old; 5.32±0.34 kg). Treatments were spray-dried plasma protein (SDPP; control), soy protein concentrate (SPC) and RPC (phase 1), and dried porcine soluble (DPS; control), SPC and RPC (phase 2). An ileal digestibility trial was also conducted to compare digestibility of amino acids in the tested protein sources. In expt. II, 160 weaning pigs (L×Y×D; 21 d-old; 5.65±0.35 kg) were used in a 5-week feeding trial to determine the optimal inclusion level of RPC in the diet. Treatments were control (9% SPC), and three levels of RPC instead of SPC in the diets (3, 6 and 9%). During phase 1, pigs fed SDPP showed better (p<0.05) ADG and FCR compared with those fed SPC or RPC, while there was no difference in ADFI among treatments. During phase 2, however, pigs fed DPS showed lower (p<0.05) ADG than those fed SPC or RPC. During the total period, there were no significant differences in ADG, ADFI and FCR among treatments. The apparent ileal digestibilities of his, lys, phe, thr and met were not different among the tested protein sources. The apparent ileal digestibilities of arg, ile, leu and val were lower (p<0.05) in RPC than SDPP. The true ileal digestibilities of arg and leu were lower (p<0.05) in RPC than SDPP and SPC. However, that of met was higher (p<0.05) in RPC than SDPP. In expt. II, there were no significant differences in ADG and FCR when SPC was substituted with RPC up to 9% during the total period. In conclusion, based on our experimental results, RPC would replace SPC in the complex prestarter diet, which is somewhat cheaper than SPC. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 3 : 384-389)