Changes In Proximate Composition Research Articles

Evaluation of lauric acid enhancement of black soldier fly larvae from coconut.

The current study evaluated the potential enhancement of lauric acid (LA) in black soldier fly, Hermetia illucens, (L.) (Diptera: Stratiomyidae) larvae (BSFL), a source of this short-chain fatty acid which has antimicrobial and immunostimulatory properties. Replicate groups of BSFL were reared on either the coconut or Gainesville diet for 7 days. After the rearing period, BSFL were harvested, purged, dried, and subjected to proximate, fatty acid and amino acid compositions, and pepsin digestibility analyses. Results demonstrate changes in proximate composition. BSFL reared on the coconut had significantly (P = 0.002) higher lipid content (47.3% vs. 25.2%) on a dry-matter basis. The LA concentration in BSFL produced on the coconut was 31% greater than those reared on Gainesville, resulting in almost 150% more LA. Furthermore, BSFL-fed coconut had reduced crude protein (29.7% of dry weight) and ash (3.7% of dry weight) relative to those fed Gainesville (43.4% and 7.5% for crude protein and ash, respectively) but higher pepsin digestibility (91.0% vs. 87.0%). The relative amounts of various amino acids in the 2 BSFL meals did not differ extensively, with statistically lower concentrations of only phenylalanine and tryptophan and higher concentrations of alanine, arginine, isoleucine, leucine, and serine in BSFL reared on coconut. Results demonstrate that the nutritional composition of BSFL can be manipulated, and an enhancement of LA concentrations of 150% was achieved with coconut, which has value for BSFL as a feed for various livestock, including aquaculture. Lower protein content is a tradeoff in terms of BSFL value as a feed additive.

Near-Infrared Spectroscopy and Chemometrics for Effective Online Quality Monitoring and Process Control during Pelagic Fishmeal and Oil Processing.

Near-infrared spectroscopy has become a common quality assessment tool for fishmeal products during the last two decades. However, to date it has not been used for active online quality monitoring during fishmeal processing. Our aim was to investigate whether NIR spectroscopy, in combination with multivariate chemometrics, could actively predict the changes in the main chemical quality parameters of pelagic fishmeal and oil during processing, with an emphasis on lipid quality changes. Results indicated that partial least square regression (PLSR) models from the NIR data effectively predicted proximate composition changes during processing (with coefficients of determination of an independent test set at RCV2 = 0.9938, RMSECV = 2.41 for water; RCV2 = 0.9773, RMSECV = 3.94 for lipids; and RCV2 = 0.9356, RMSECV = 5.58 for FFDM) and were successful in distinguishing between fatty acids according to their level of saturation (SFA (RCV2=0.9928, RMSECV=0.24), MUFA (RCV2=0.8291, RMSECV=1.49), PUFA (RCV2=0.8588, RMSECV=2.11)). This technique also allowed the prediction of phospholipids (PL RCV2=0.8617, RMSECV=0.11, and DHA (RCV2=0.8785, RMSECV=0.89) and EPA content RCV2=0.8689, RMSECV=0.62) throughout processing. NIR spectroscopy in combination with chemometrics is, thus, a powerful quality assessment tool that can be applied for active online quality monitoring and processing control during fishmeal and oil processing.

Effect of different reheating processes and conditions on the nutritional, functional, and microbiological properties of cow meat.

The objective of this study was to evaluate the effect of different reheating methods and conditions on the proximate composition, mineral content, oil quality, and functional and microbiological properties of cow meat. For this, a survey was carried out to identify the reheating methods used in the community. For this study, 8.6 kg of raw beef was used and group 1 (500 g) served as raw control. The remaining 8.1 kg was boiled for 30 min in 5 L of water. Four hundred grams of boiled beef was removed and served as cooked control (group 2). The remaining 3688 g was divided into four groups of 922 g, which were, respectively, divided into subgroups of 307 g. The four sets of subgroups were, respectively, reheated by boiling, frying, microwaving and oven roasting for 3 days. Reheating was done three times a day and samples were collected at the end of each day for further analysis. Changes in proximate composition, mineral content, oil quality, functional properties, and microbiological count were evaluated using standard methods. Results showed that frequent reheating of food was the most used preservation method of cooked food, and boiling and steaming were the most used methods. Reheating time significantly reduces the protein, mineral content, and oil quality of cow meat in general. For the functional properties, reheating methods/conditions generally increased the water-holding capacity, loose and packed bulk densities as well the pH of the meat. Reheating by frying increased the porosity and Hausner ratio of the meat powder while all the reheating treatments reduced the swelling capacity and titratable acidity of cow meat powder. Generally, the reheating methods and duration significantly reduced the bacterial count of cow meat powder. Cow meat should not be reheated for more than 2 days in order to preserve its physiochemical properties.

Changes in Fish Flakes Prepared from Pangas (Pangasianodon hypophthalmus) Mince during Storage

Aims: This study was conducted to prepare fish flakes using Pangas (Pangasianodon hypophthalmus) mince with wheat flour and other ingredients and to determine the sensory and physicochemical changes of fish flakes during storage.
 Place and Duration of Study: Fish Processing and quality control laboratory of the department of Fisheries Technology, Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh. Study duration was from June 2021-July 2022.
 Methodology: Initially, fish flakes were prepared using 30%, 40% and 50% fish mince with other ingredients. Among the samples, fish flakes containing 50% fish mince (S3N) gained the highest score in the conducted panel test. During the storage of 9 months at room temperature (28° to 32°C) in polythene zipper packets, different properties of S3N was analyzed at 15- and 30-days of intervals.
 Results: The changes in proximate composition of the sample during storage indicated that only minor alterations occurred in fish flakes. During this study period no remarkable changes observed in the color, flavor, texture of fish flakes. Mold growth on fish flakes samples was not found.
 Conclusion: The findings of this study can be concluded as, popular snack item like fish flakes can be prepared using pangas fish mince by incorporating with other ingredients which can be stored at room temperature (28° to 32°C) in polythene zipper packets for 270 days without any major changes in compositional and consumption quality.

Chronic Stress Decreases Lactation Performance.

The ability to provision offspring with milk is a significant adaptive feature of mammals that allows for considerable maternal regulation of offspring beyond gestation, as milk provides complete nutrition for developing neonates. For mothers, lactation is a period of marked increases in energetic and nutritive demands to support milk synthesis; because of this considerable increase in demand imposed on multiple physiological systems, lactation is particularly susceptible to the effects of chronic stress. Here, we present work that explores the impact of chronic stress during lactation on maternal lactation performance (i.e., milk quality and quantity) and the expression of key milk synthesis genes in mammary tissue using a Sprague-Dawley rat model. We induced chronic stress using a well-established, ethologically relevant novel male intruder paradigm for 10 consecutive days during the postpartum period. We hypothesized that the increased energetic burden of mounting a chronic stress response during lactation would decrease lactation performance. Specifically, we predicted that chronic exposure to this social stressor would decrease either milk quality (i.e., composition of proximate components and energy density) or quantity. We also predicted that changes in proximate composition (i.e., lipid, lactose, and protein concentrations) would be associated with changes in gene expression levels of milk synthesis genes. Our results supported our hypothesis that chronic stress impairs lactation performance. Relative to the controls, chronically stressed rats had lower milk yields. We also found that milk quality was decreased; milk from chronically stressed mothers had lower lipid concentration and lower energy density, though protein and lactose concentrations were not different between treatment groups. Although there was a change in proximate composition, chronic stress did not impact mammary gland expression of key milk synthesis genes. Together, this work demonstrates that exposure to a chronic stressor impacts lactation performance, which in turn has the potential to impact offspring development via maternal effects.

Effects of different cooking methods on the proximate composition and physical properties of Brown shrimp (Metapenaeus dobsonii) during cooking and freezing cycle.

Present study aimed to evaluate the changes in proximate composition and physical attributes in brown shrimp (Metapenaeus dobsonii) exposed to different methods of cooking followed by freezing. For this, three different grades (100/200, 200/300, and 300/500 numbers per kg) of brown shrimp were cooked at 90 °C till the core temperature of the product reaches 85 °C using hot water, steam, and microwave (400 W) techniques. The changes in yield, cooking loss, proximate composition, textural, and colour profile were assessed for cooked shrimps. The cooking loss was higher for larger grades of shrimp, whereas shrimp cooked using hot water exhibited the highest cooking loss. Lowest cooking loss was observed for microwave-cooked shrimp. Moisture content decreased after cooking whereas protein, fat, ash, and calorie content increased. After cooking, different grades of shrimp showed an increase in their lightness (L*), redness (a*), and yellowness (b*) values. The smaller grade shrimp exhibited lower value for cohesiveness, hardness, chewiness, and gumminess. Different cooking techniques yielded cooked shrimp of varying hardness values.

Incorporation of betel leaf extract provides oxidative stability and improves phytochemical, textural, sensory and antimicrobial activities of buffalo meat sausages

The antioxidant effect of betel leaf extract (BLE) on lipid and protein oxidation, microbial count and physicochemical attributes was investigated in meat sausages during refrigerated storage at 4 ± 1 °C. Buffalo meat sausages were developed after incorporating 0, 250, 500 and 750 mg kg−1 of BLE (BLE0, BLE1, BLE2 and BLE3) respectively. The sausages showed no changes in proximate composition due to BLE inclusion, but there was an improvement in microbial quality, color score, textural properties and lipid and protein oxidative stability. Further, higher sensory scores were observed for the BLE-incorporated samples. The images from scanning electron microscopy (SEM) revealed a reduction in surface roughness and unevenness showing microstructure modification in BLE treated sausages compared to the control sausages. Hence, to improve the storage stability and impede the rate of lipid oxidation in sausages, BLE incorporation proved to be an effective strategy.

NUTRITIONAL VALUE ASSESSMENT AND PROXIMATE COMPOSITION OF GAMMA IRRADIATED GRAPES


 
 
 Grapes (Vitis vinifera L.) belong to the family Vitaceae that are the best source of energy. The present research was focused to increase the shelf life and controlling the amount of fruit losses by optimizing the dose of gamma radiation and proximate analysis post gamma radiation. In the present study, grape samples were exposed to three doses of gamma radiation i.e. 0.5, 0.8 and 1 KGy. Nutritional value of grapes after gamma radiation was analyzed to determine the change in proximate composition. Through experimentation, it was observed that 0.8 KGy was optimized dose as the sensory properties remained unchanged and shelf life of grapes was increased up to 14 days. However the overall effect of gamma radiation enhanced the shelf life with a non-significant effect. Hence, gamma radiation is a promising technique in increasing country’s economy.
 
 

Characterization of physicochemical, rheological, aroma, and sensory properties of spreadable processed cheese supplemented with chia, quinoa, and teff seeds

The physicochemical, rheological, aroma, and sensory properties of spreadable processed cheese supplemented with chia, quinoa, and teff seeds were evaluated. The changes in proximate composition, color values, rheological parameters, volatile profile, sensory, and microbiological properties of the cheese samples stored at 4 °C for 90 days were assessed. Significant differences in the initial contents of dry matter, protein, and fat were observed among the cheese samples. The pH was affected by the storage time and type of added pseudocereal. Moreover, the storage time and type of pseudocereal interaction affected the titratable acidity and color parameters of the cheese samples. The water-soluble nitrogen content increased slightly in all cheese samples during storage. The cheese samples supplemented with pseudocereals exhibited a pseudoplastic behavior. The consistency index of the cheese samples ranged from 2.277 to 2.550 Pa.sn, and the flow behavior index ranged from 0.528 to 0.665. The counts of total coliform and yeast-mold in all cheese samples were <1 log CFU/g cheese, and the counts of total mesophilic aerobic bacteria ranged from 2.21 log CFU/g cheese to 2.76 log CFU/g cheese. A total of 27 volatile compounds, consisting of acids, aldehydes, ketones, esters, and terpenes, were identified in the cheese samples. The amounts of butanoic acid, hexanoic acid, octanoic acid, and nonanoic acid in all cheese samples were higher than that of other volatiles, with the amounts ranging from 639 µg/kg to 3284 µg/kg, 711.20 µg/kg to 2723.27 µg/kg, 187.60 µg/kg to 722.71 µg/kg, and 75.42 µg/kg to 206.02 µg/kg, respectively. The most preferred cheese in terms of sensory properties was the control sample, followed by the SCT, SCQ, and SCC samples.

Nutrient compositional variation and interrelationship in the muscle of wild and plastic-reared brachyuran

Edible brachyurans are recognized as a popular source of food due to their delicious taste and nutritional quality. This study investigated the nutrient compositional variation and interrelationship in the muscle of wild and plastic-reared Cardisoma armatum. The plastic-reared crab had 27.81 ± 2.29 g 100 g-1 protein while crab from the wild contained 22.45 ± 2.65 g 100 g-1 protein. The difference in protein content of plastic-reared and its counterpart from the mangrove swamp was not significantly different (p > 0.05). This is also true of other proximate composition except that wild crabs were slightly higher in both crude fat (2.68 ± 0.35 g 100 g-1) and carbohydrate (5.89 ± 3.05 g 100 g-1). Generally, the total energy contributed due to protein, carbohydrate and fat in the tissues of both wild and plastic-reared C. armatum are similar. In the wild crab, contents of calcium (16083.27 ± 2127.90 mg 100 g-1) and phosphorus (1191.42 ± 199.21) were relatively higher, while contents of magnesium (368.69 ± 111.05 mg 100 g-1), sodium (125.30 ± 11.18 mg 100 g-1) and potassium (87.36 ± 7.27 mg 100 g-1) were relatively higher in plastic-reared crabs. All significant mineral ratios in wild and plastic-reared C. amartum fall within acceptable range. The positive relationship in the nutritional quality indicates that changes in proximate composition are associated with changes in mineral contents of the crab tissue.

Influence of different oilseed cake incorporation on batter rheology, proximate composition, texture, antioxidant and sensory properties of wheat flour muffins

SummaryOilseed cake flour (OCF) can be incorporated into baked foods to improve nutritional properties and solve problems related to the food sustainability. In this study, wheat flour muffins were prepared by incorporating flaxseed (FCF), sesame (SCF), mustard (MCF), nigella (NCF) and groundnut (GCF) cake flour at 10%, 20% and 30% levels. The batters prepared by incorporating different OCF were evaluated for viscoelasticity (G′, G″ and tan δ) and the changes in proximate composition, texture, antioxidant activity, sensory properties and shelf life of muffins were studied. The OCF incorporation had increased the batter viscoelasticity (increased G' and G"), hardness, springiness and gumminess while decreased the cohesiveness of muffins. The ash, fat, protein, phenolic content and radical scavenging activity increased, while moisture content, colour values (crust and crumb), bake loss, specific volume and height of muffins decreased with OCF incorporation. The 30%NCF‐incorporated muffins had longer shelf life and lower sensory scores for colour, taste, odour, texture and overall acceptability. The 10%FCF‐ and 10%SCF‐incorporated muffins had better texture, nutritional profile and shelf life while wheat‐alone muffins had comparable hardness, cohesiveness, specific volume and sensory properties.

Rabbits Divergently Selected for Total Body Fat Content: Changes in Proximate Composition and Fatty Acids of Different Meat Portions.

Simple SummaryThe purpose of the investigation was to determine the effect of the selection for the total fat content of the rabbit body on the fat content and fatty acid composition of different meat cuts. The higher the fat content of the given meat, the more effective the selection was. Authors found that the meat of fatter rabbits is healthier, which can be used in the production of baby food.The present research studied the potential of a four-generation divergent selection (Pannon maternal rabbit lines) based on the total body fat content to create two rabbit lines with different meat attributes: a Fat line to deliver greater amounts of healthy fatty acids for newborns and infants, and a Lean line intended to provide lean meat for everyday consumption. Selection was based on the fat index calculated in 10-week-old live rabbits by means of computed tomography (CT). For each generation, 60 rabbits/line were fed ad libitum with commercial pellet from weaning (5 weeks) to slaughter (11 weeks). A total of 15 rabbits/line were randomly selected for meat quality evaluations: the longissimus thoracis et lumborum muscles (LTLs), hind legs (HLs), forelegs (FLs) and abdominal wall (AW) were analyzed for their proximate composition and fatty acid (FA) profile. FA contents were also calculated. Results highlighted that it was possible to obtain leaner meat for everyday consumption in most meat portions starting from generation 4 (7.93 vs. 11.9, 5.10 vs. 5.98 and 7.26 vs. 10.9 g of lipids/100 g of meat in Lean and Fat groups for the FLs, HLs and AW, respectively). The sole exception was the LTLs, which were not affected by the divergent selection. The total PUFA amount increased in FL and AW (p < 0.05) portions of the Fat line only, attributable to a greater n-3 amount (151 vs. 216 and 73 vs. 143 mg/100 g of meat in Lean and Fat groups for the FLs and AW, respectively).

Effect of bioactive-rich mango peel extract on physicochemical, antioxidant and functional characteristics of chicken sausage

This research was focused to unveil the role of natural antioxidants in meat products based on the current inclination of consumers and food industries towards natural antioxidants. Chicken sausages MPE0, MPE2, MPE4 and MPE6, developed by the incorporation of 0%, 2%, 4% and 6% mango peel extract (MPE) respectively were investigated. Chicken sausages showed no significant changes in proximate composition, pH and cooking parameters however, significant (P < 0.05) improvement in lipid oxidative stability, antioxidant activity, phenolic content, overall color, and DPPH activity occurred due to MPE incorporation. MPE4 sausages witnessed least effect on color parameters, highest reduction in carbonyl content and radical scavenging activity, suggesting the incorporation of 4% MPE for quality amelioration of chicken sausages. The study showed that the MPE modified sausages exhibited superior thiol content and reduced carbonyl content that hampers protein oxidation; hence MPE incorporation could be considered an effective approach.

Changes in enzymatic activity and in vitro protein digestibility of four millet varieties upon germination and quality evaluation of cookies prepared from germinated millet composite flours

The millet kernels of four millet varieties (foxtail, finger, and red and white proso millets) were germinated for 24, 48, and 72 h at 30 and 35°C. Changes in proximate composition, activity of α-amylase, cellulase, and protease, and in vitro protein digestibility, were determined in whole flours obtained from the germinated seeds. Germination increased protein content while decreasing ash and moisture contents in most millet varieties. Enzyme activities in all the millets were influenced by germination time and temperature (p < 0.05). α-Amylase activity in foxtail and red proso millet significantly increased during the germination (from 1774.05 to 2643.18 U/g, and from 1608.19 to 1816.84 U/g, respectively at 30°C). Protein digestibility increased after germination and correlated with protein content, α-amylase, and protease activities. Cookies made from the germinated foxtail composite flour presented a comparable sensory acceptance to the reference cookies made from wheat flour. Practical applications Germination increased protein content while decreasing ash and moisture contents in most studied millet varieties. Enzyme activities (α-amylase, cellulase) in all the millets, and especially in foxtail millet, were influenced by germination time and temperature. Protein digestibility increased after germination and correlated with protein content, α-amylase, and protease activities but was reduced in the formulated cookies.

Effect of Salting on Mechanical Drying of Pangasius hypophthalmus

A study was conducted during 2016 to evaluate the effect of salt and mechanical drying on Pangasius at Central Institute of Fisheries Education, Andheri, Mumbai, India. In this study, the salted and unsalted Pangasius was mechanically dried at 60°C temperature and the quality of the dried Pangasius was evaluated. The quality parameters include the changes in proximate composition, physicochemical parameters [total volatile base nitrogen (TVBN), peroxide value (PV), free fatty acid (FFA), pH, thiobarbituric acid reactive substances (TBARS), salt, water activity], microbial enumeration (total viable count (TVC), Escherichia coli, Staphylococcus spp.) and sensory evaluation. The colour characteristics, percentage yield and storage stability of the product was also evaluated. From the results, it was observed that the protein and ash content of unsalted dried Pangasius was higher than salt dried Pangasius. From the results of physicochemical changes, it was observed that PV, FFA, TVBN, TBARS and salt content were higher in salt dried Pangasius. The TVBN, PV and salt content of salt dried Pangasius were 24.75 mg N 100 g-1, 4.17 meq O2 kg-1 fat and 14.55% respectively which were higher than the Unsaltd dried Pangasius. The salt dried Pangasius had higher L* value but lower a* and b* value than unsalted dried Pangasius. The unsalted dried Pangasius was unstable during storage whereas salt dried Pangasius was stable. Based on the results, it was concluded that salt drying is the most effective method of preservation for drying Pangasius at 60°C.

The preservative impact of the brown seaweed ( Padina tetrastromatica ) extract on the quality of tilapia ( Oreochromis mossambicus ) during chilled storage

In this study, different solvents were screened for the extraction of phenolic compounds from brown seaweed (Padina tetrastromatica). Among the methods, 50% (v/v) methanol gave maximum yield having higher phenolic content with antioxidant and antimicrobial activities. The methanol free crude extract was used as a natural preservative for chilled stored tilapia by giving dip treatment at different concentrations as control (T0), 0.5% (T1) 1% (T2) 1.5% (T3), and 2% (T4) (v/v) before chilled storage. Sampling was done on the 0th, 7th, 14th, 17th, 21st, 23rd, and 25th days, respectively. The changes in proximate composition, total volatile base nitrogen, free fatty acid, peroxide value, thiobarbituric acid reactive substance, total viable count and sensory evaluation were analyzed. The onset of spoilage was delayed in seaweed treated samples. Tilapia got 6 days' shelf life extension, when treated with 1%–1.5% of seaweed extract as compared to the control sample. Novelty impact statement The present study showed the potential of seaweed as a natural preservative in chilled stored fish. Seaweed is a good source of phenolic compounds that has potent antioxidant and antimicrobial properties, which is expected to be responsible for the preservative effect.

Use of faba bean (Vicia faba L.) hulls as substrate for Pleurotus ostreatus – Potential for combined mushroom and feed production

A circular concept involving use of faba bean hulls for production of oyster mushrooms (Pleurotus ostreatus (Jacq.) P. Kumm.) and the post-harvest residues for feed purposes was evaluated. Faba bean hulls are a waste remaining after the beans are dehulled to decrease the content of anti-nutritional factors and increase the food value of the beans. Faba bean hulls proved very suitable as substrate for production of oyster mushrooms, with biological efficiency of 109 ± 28%. The fruiting bodies produced were comparable to commercially sold mushrooms in terms of morphology, protein content, protein quality, and chemical composition. After mushroom harvest, 48.4 ± 0.6% of initial dry weight (dwt) of the substrate remained and showed significant changes in proximate composition, with an increase in protein concentration from 207.9 ± 8.6 to 346.6 ± 16.5 g kg−1 dwt and a significant increase in 14 of 16 amino acids analyzed, including methionine. Concentrations of the anti-nutritional compounds vicine and convicine were below the detection limit after mushroom harvest, while their initial concentration was 5.7 ± 0.1 and 1.4 ± 0.04 g kg−1 dwt, respectively. Tannin concentration was reduced by approximately 50%, to a final level of 9.0 ± 1.6 g kg−1 dwt. Comparison of the spent mushroom substrate with a commonly used feedstuff for pigs indicated potential for the spent substrate to be a valuable protein source in pig diets. This study demonstrates the potential for achieving complete circular use of agro waste and has implications for development of production systems well suited in the biobased society.

Changes in Proximate Composition, Vitamin C and β-Carotene Contents of Oven Dried Pawpaw (Carica papaya) Fruit as Influenced by Pretreatment Methods

A common way of maintaining essential nutrients in fruits and vegetables is through novel food processing techniques such as pretreatment. This study investigated the influence of pretreatment methods on the proximate composition, vitamin C and β-carotene contents of oven dried pawpaw. Fresh, ripe pawpaw fruit were peeled, sliced and pretreated with three pretreatments – ascorbic acid dip (0.45% w/v), honey dip (0.25% v/v) and steam blanching (100 °C). The fruit slices were soaked in ascorbic acid and honey solutions for 4 min while steam blanching was done for 2 min. Untreated pawpaw sample served as the control. The treated and control samples were dried at an average temperature of 65 °C. Results showed that vitamin C of dried pawpaw samples pretreated with honey dip had the highest retention of vitamin C (116.05 mg/100g) compared to ascorbic acid treated (98.90 mg/100g), steam blanched (109.02 mg/100g), and control samples (77.02 mg/100g). In terms of β-carotene, pawpaw sample treated with ascorbic acid solution had the highest value of 12.68 mg/100g. The use of honey and ascorbic acid solutions as treatments prior to drying can improve the retention of nutrients such as vitamin C and β-carotene in dried fruits.Keywords—Pretreatments, proximate properties, vitamin C, β-carotene

Effect of storage temperature and time on the fatty acids and nutritional quality of the commercial mussel (Mytilus galloprovincialis).

The effect of storage time (5, 10 and 15days) and temperature (- 20°C and + 4°C) on the biochemical composition of the Tunisian mussel (Mytilus galloprovincialis) was evaluated by investigating changes in proximate composition, fatty acids, minerals and nutritional quality indices. Lipid and protein degradations were also evaluated through several markers of oxidative damage. Results showed a significant decrease in the biochemical compounds in mussel tissues after both refrigeration and freezing processes (p < 0.01). As regards the fatty acid composition, saturated fatty acids increased significantly after both storage processes. However, polyunsaturated and monounsaturated decreased, especially after 10 and 15days of storage. The reduction of nutritional quality and mineral contents were detected after both storage processes. Markers of oxidative damage varied remarkably between fresh and stored tissues, revealing that both processes greatly influenced the nutritional quality of mussels. Overall, it is well recommended to consume fresh and stored mussels for no more than 5days in the refrigerator (+ 4°C) in order to preserve the better quality of this product and provide more benefits for human health.

Effect of Fermentation by Rhizopus oligosporus or Amylomyces rouxii on In-Vitro Starch and Protein Digestibility of Decorticated Red Sorghum (Sorghum bicolor L. Moench)

Solid substrate fermentation of cooked decorticated red sorghum was carried out by using mould Rhizopus oligosporus or Amylomyces rouxii. This study aims to investigate the growth of mould biomass by determining glucosamine and investigating the effects of fermentation on the changes in proximate composition, pH and total titratable acidity, and in-vitro starch and protein digestibility. Red sorghum was decorticated using a carborundrum discs to remove the bran. Decorticated sorghum was soaked in water (12 h for R. oligosporus and 1 h for A. rouxii fermentation), heated up to 90oC for 30 min, steamed for 30 min, and sterilized at 121oC for 20 min). Fifty g of sterile sorghum was inoculated with R. oligosporus (6.103 spore/g substrate) or A. rouxii spores (2.103 spore/g substrate) then incubated at 30oC. Samples were taken at 0, 12, 18, 24, 30, and 36 h for R. oligosporus fermentation and 0, 24, 48, 72, 120, and 168 h for A. rouxii fermentation. The results indicated that glucosamine content of fermented sorghum by R. oligosporus and A. rouxii were 4.49 and 11.72 mg/g dry matter at the end of fermentation, respectively. R. oligosporus hydrolyzed up to 11.4% of initial starch and 63.4% by. A. rouxii. There were more protein and fat losses in R. oligosporus fermentation than A. rouxii. Both fermentations produced acid and lowered pH to about 3.0, but pH went up to 4.0 at the end of R. oligosporus fermentation. Mould fermentation improved in-vitro starch digestibility, in A. rouxii it went up from 31.3% to 37.9% and down again to 11.4% at the end of fermentation. In R. oligosporus fermentation, it went up to 35.4%. In-vitro protein digestibility went up from about 35.0% to 37.0% and to 51.8% by R. oligosporus and A. rouxii fermentation, respectively.