Quality changes in fish sausages supplemented with pangas protein isolates as affected by frozen storage and casing material.

Influence of pangas protein isolates (10PI) and casing material on frozen storage (-18 °C) characteristics of pangas mince sausages was studied for a period of three months along with control sausages (CO). The expressible fluid content of sausage emulsion increased as storage progressed to 3 months, reaching 31.32 and 17.57 g 100 g-1 for control and 10% PI emulsions, respectively. Water holding capacity and cooking yield values showed a gradual and significant (p < 0.05) reduction with progress in the storage time. The G' and G″ values decreased during storage, indicating the change in protein structure and gelling ability. Sausages packed in LDPE casings had higher oxidation and bacterial counts than sausages packed in cellulose casings. Irrespective of the casing material and protein isolates, the sensory scores varied non-significantly in all the sausages during the initial storage phase. After three months, sausages from COCL and 10PICL were still acceptable with sensory scores of 5.6 and 5.8, respectively, indicating better quality of sausages stuffed into cellulose casings than LDPE casings. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05222-1.

Utilization of protein isolates from rohu (Labeo rohita) processing waste through incorporation into fish sausages; quality evaluation of the resultant paste and end product.

BACKGROUND: Fish processing waste could be valorized by recuperating the nutrients for human consumption. Employing a suitable process would address the pollution problems associated with its dumping and would contribute to food security. In this study, protein isolates obtained from rohu (Labeo rohita) processing waste through the pH shift process (pH 13.0) were valorized through incorporation into pangasius (Pangasius pangasius) mince sausages (0.0, 50, 100, 250, and 500 g kg-1 ). These sausages were analyzed for their proximate composition, and their physical and eating quality. RESULTS: Increasing the isolate content (11.57% to 16.14%) in sausages increased their protein content and whiteness values (P < 0.05). At 250 g kg-1 level, the cooking yield was maximum, and the expressible fluid content of paste was minimum. Moreover, adding rohu protein isolates in pangasius mince increased the expressible moisture and decreased its folding and gel strength values (P < 0.05). The gel strength values were highest for the sausages without isolates (2648.67 g cm). In contrast, in the sausages containing 250, 100, and 500 g kg-1 isolate, the values were determined to be 847.88, 731.21, and 611.06 g cm, respectively. Replacing pangasius mince with rohu protein isolates had a non-significant effect on the sensory attributes of the sausages. CONCLUSION: Replacing pangasius mince with rohu protein isolates at 250 g kg-1 resulted in superior quality sausages compared with other levels tested. Incorporating rohu protein isolates in fish sausages improved the nutritional value without significantly reducing their eating quality. The findings of this study indicate promising potential for developing nutrient-rich foods using fish protein isolates. © 2021 Society of Chemical Industry.

Effect of organic acid on recovery yields and characteristics of rohu (Labeo rohita) protein isolates extracted using pH shift processing.

BACKGROUND: Proteins recovery using hydrochloric acid (HCl) in acid-aided solubilization could cause greater loss in its functionality over alkali-aided solubilization. Moreover, using HCl in edible foods is also a health concern. Replacing HCl with organic acids for acid-aided solubilization could address these problems. The aim was to study the effect of organic acid (glacial acetic acid) as a replacement for HCl during pH shift processing on the characteristics and functionality of rohu (Labeo rohita) protein isolates. Rohu proteins were obtained by solubilizing at pH 3.0 and pH 11.0 using glacial acetic acid and sodium hydroxide (10 mol L-1 ). RESULTS: Results showed that solubilization at pH 11.0 gave higher protein yields (766.8 ± 2.4 g kg-1 ) compared to solubilization at pH 3.0 (735.7 ± 7.1 g kg-1 ) (P < 0.05). Isolates from acid-aided solubilization had higher whiteness and total pigment content over isolates obtained by alkali-aided solubilization. Rohu isolates recovered by alkaline solubilization showed higher water and oil holding capacity, gel strength, folding scores, foaming and emulsion capacity than acid processed isolates (P < 0.05). Solubilization of rohu proteins using glacial acetic acid produced isolates with low breaking force (149.0 g), low storage modulus (G') values and low folding test score (1.0) over the alkaline isolates (P < 0.05). CONCLUSION: Results indicated that, recovering rohu proteins using organic acid (glacial acetic acid) could produce isolates with poor functional properties, while using the organic acid to precipitate the proteins solubilized by alkali-aided processing could produce proteins with better yields and functionality. © 2019 Society of Chemical Industry.

Incorporating Optical Coherence Tomography in the Cataract Preoperative Armamentarium: Additional Need or Additional Burden?

PURPOSE: To determine the usefulness of preoperative optical coherence tomography (OCT) examination to detect asymptomatic macular abnormalities in patients scheduled for cataract surgery. METHODS: Design: Prospective, interventional case series. SETTING: Iladevi Cataract and Visakha Eye Center, Ahmedabad, India. STUDY POPULATION: Patients undergoing cataract surgery and intraocular lens (IOL) implantation for senile cataracts. Preoperatively no retinal/macular pathology was identified on clinical evaluation. INTERVENTION: All eyes underwent macular 5-line raster evaluation using spectral-domain OCT before and after cataract surgery (monthly for 3 months). Central subfield thickness (CST) analysis was done. OUTCOME MEASURES: The primary outcome measure was determining the incidence of asymptomatic retinal lesions on OCT examination in clinically "normal" maculas. Secondary outcome measures included documenting change in corrected distance visual acuity and OCT thickness postoperatively. RESULTS: A total of 1444 eyes were evaluated. OCT revealed asymptomatic lesions in 133 (9.21%) patients. At 3 months, all eyes showed significant median visual improvement (from 0.45 ± 0.13 logMAR to 0.06 ± 0.08 logMAR; P = .015) and insignificant median CST change (from 223.34 ± 21.1 µm to 249.12 ± 19.24 µm; P = .19). One eye showed increased vitreomacular traction (3 months). Patients with asymptomatic lesions did not have significantly worse postoperative visual outcomes at 3 months (from 0.52 ± 0.16 logMAR to 0.14 ± 0.1 logMAR; P = .12). CONCLUSION: A total of 9.21% patients with clinically normal maculas had subtle pathology detected on OCT, but this subset of patients did not have worse postoperative visual outcomes compared to eyes with normal OCT scans. Thus, a careful pre-cataract surgery fundus examination remains an essential part of the presurgical patient evaluation.

Antioxidant and antimicrobial properties of grape and papaya seed extracts and their application on the preservation of Indian mackerel (Rastrelliger kanagurta) during ice storage.

Antioxidant properties of grape (GSE) and papaya seed extracts (PSE) were tested in vitro at varied concentrations and growth inhibition were seen against gram positive and gram negative bacteria by disc diffusion method. The results revealed that GSE contain four times higher phenolic and six folds higher flavonoid content than PSE. The antioxidant properties of GSE and PSE showed dose dependent activities and were comparatively much higher in GSE. Linoleic acid model of GSE and PSE displayed 67.67 and 46.43 % of inhibition respectively at 500 mg/L. The effect of dip treatment by GSE and PSE at a concentration of 500 and 1000 mg/L respectively on the quality changes of Indian mackerel (Rastrelliger kanagurta) in iced condition were assessed using chemical, microbiological and sensory parameters along with chilled whole control (CWC). The inhibition of primary and secondary lipid oxidation products by GSE at 500 mg/L was comparable to BHT at 200 mg/L. GSE exhibited higher antimicrobial activity on gram-positive strains compared to PSE and reduced the formation of volatile bases significantly. On the day of sensory rejection for CWC, the formation of trimethylamine and total volatile base nitrogen were reduced by 32.27 and 31.85 % in GSE samples and 19.01 and 24.70 % in PSE samples respectively. The dip treatment of GSE increased the shelflife of mackerel up to 15 days, PSE by 12 and 9 days for CWC during ice storage. Therefore, it can be concluded that, GSE can be used as a promising natural preservative and a substitute to the synthetic counterparts.

Influence of Button mushroom (Agaricus bisporus) on quality and refrigerated storage stability of patties prepared from sutchi catfish (Pangasius hypophthalmus).

The ability of button mushroom (Agaricus bisporus) in changing physical, chemical, microbial and sensory properties of fish patties prepared from sutchi catfish (Pangasius hypophthalmus) was investigated. Two batches of fresh patties were prepared, one batch was treated with 15 % button mushroom (TP) and other batch was a control (CP) without mushroom. The patties were packed in polythene bags and stored under refrigerated condition (6 ± 2 ºC) without adding any preservatives for the estimation of storage stability. The analyses of patties were conducted at regular intervals of 3 days. The results showed that, Peroxide value, Thiobarbituric acid value, Free fatty acids increased significantly in CP at the end of 12 days whereas the TP was within the acceptable limit up to 16 days. Total volatile base nitrogen and Trimethylamine nitrogen also showed a similar trend. The Total plate count and Aerobic spore formers showed an increasing trend in CP when compared to TP. The sensory scores showed that the overall acceptability of CP were lower than TP, which was acceptable even after 16 days of storage. The present study showed that, the quality and storage stability of TP were observed to be in good condition up to 16 days and started deteriorating 20th day onwards, whereas the CP were acceptable only up to 12 days. Therefore it can be recommended that, addition of 15 % of button mushroom to sutchi catfish patty not only increases the nutritional quality but also increases the shelf life of patties under refrigerated storage.

Effect of oil of hydnocarpus on wound healing.

Oil of hydnocarpus has been replaced by other chemotherapeutic agents which have a better mycobactericidal effect. However, none of the currently used antileprosy drugs has been reported to have a positive effect in wound healing. Anecdotal reports claim that leprosy patients who have taken capsules containing oil of hydnocarpus orally have shown more rapid wound healing than those not receiving it. In view of these reports, a pilot experimental study was undertaken to determine the effect of the oil of hydnocarpus in wounds experimentally inflicted on male Wistar rats. The wound-healing effect of oil of hydnocarpus was studied with reference to collagenation and the strength of the scar tissue. The drug-treated group showed a significant increase in body weight and strength of scar tissue in the incision model and, also, increased strength of the collagen tissue and hydroxyproline content in the dead space model. The results of this pilot study indicate that the oil of hydnocarpus, which also has antileprotic activity, could be a useful adjunct in the healing of wounds and ulcers in leprosy patients.