Recent advances in modified starch based biodegradable food packaging: A review

This study reviews the importance of resistant starch (RS) as the polymer of choice for biodegradable food packaging and highlights the RS types and modification methods for developing RS from native starch (NS). NS is used in packaging because of its vast availability, low cost and film forming capacity. However, application of starch is restricted due to its high moisture sensitivity and hydrophilic nature. The modification of NS into RS improves the film forming characteristics and extends the applications of starch into the formulation of packaging. The starch is blended with other bio-based polymers such as guar, konjac glucomannan, carrageenan, chitosan, xanthan gum and gelatin as well as active ingredients such as nanoparticles (NPs), plant extracts and essential oils to develop hybrid biodegradable packaging with reduced water vapor permeability (WVP), low gas transmission, enhanced antimicrobial activity and mechanical properties. Hybrid RS based active packaging is well known for its better film forming properties, crystalline structures, enhanced tensile strength, water resistance and thermal properties. This review concludes that RS, due to its better film forming ability and stability, can be utilized as polymer of choice in the formulation of biodegradable packaging.

Dairy farmers' knowledge, awareness and practices regarding bovine lameness in Malaysian dairy farms

Given the data paucity on dairy farmers' perspectives regarding bovine lameness and hoof diseases, particularly in South East Asian countries, this study was conducted to assess the knowledge, attitude and practices toward lameness and hoof health among dairy cattle farmers in Malaysia. An online-based and face-to-face survey was conducted among 114 dairy farmers from four states in Peninsular Malaysia. Data were analysed using descriptive statistics, principal component analysis and an independent sample t-test. Overall, farmers demonstrated satisfactory knowledge and attitude regarding lameness and its impact on dairy cattle welfare and production. Lameness was ranked the second most important health issue in dairy farms after mastitis. Notably, 90% reported the presence of at least one lame cow on their farms, and 55% stated lameness as the reason for culling their cows. While sole ulcer was the hoof lesion mostly identified by farmers, 75% of them underestimated lameness prevalence on their farms and rarely implemented management strategies such as preventive hoof trimming and footbath. Farmers' educational qualification influenced their understanding of the impact of lameness on dairy cattle production. Despite reflecting satisfactory knowledge and attitude towards lameness in dairy cows, farmers in this study need to improve their current management practices to address lameness problem in their herds. Educating farmers on the importance of early detection and prompt treatment, and preventive measures are crucial for lameness control and improving hoof health in these dairy farms.

Extraction and characterization of starch from low-grade potatoes and formulation of gluten-free cookies containing modified potato starch

Potatoes are among the leading staple crops due to nutritional value and high demand. The undersized and damaged potatoes are considered low grade and mainly dumped as a waste or used in animal feed. The study aimed to extract starch from low grade potatoes, its modification to improve the starch properties and formulation of gluten free cookies using modified starch (MS). The starch was extracted from low-grade potatoes of three varieties known as Asterix, Kruda and Mosaic, using the water steeping method. The native starch (NS) was modified using lintnerization and repetitive autoclaving. MS contains high amylose content which is associated with health benefits. NS and MS were characterized for amylose content, color attributes, granular morphology, water solubility index (WSI), water absorption index (WAI), thermogravimetric analysis (TGA) and Fourier transform infrared spectrometer (FTIR) analysis. Gluten-free cookies were formulated by adding potato NS and MS. The cookies were characterized by sensory evaluation, proximate and textural analysis. The starch yield extracted from three different varieties of potatoes i.e. Asterix, Kruda, Mosaic was 11.53%, 11.32% and 11.24%, respectively. The amylose content of potato starch was significantly (p < 0.05) increased for all varieties (33.61-37.74%) after modification of NS, which was in the range of 25.71-26.60% for different potato varieties. The granules of MS were observed as amorphous structures in comparison to NS granules with smooth surfaces. The addition of MS significantly (p < 0.05) decreased the hardness of the cookies in comparison to NS. Overall, no significant difference was observed in the sensory attributes of control, NS and MS containing cookies. Therefore, in comparison to other dietary fibers, MS can be used as a functional ingredient in food products without compromising the texture and sensory attributes.

High throughput biochemical profiling, and functional potential analysis for valorization of grape peduncles

Vitis vinifera L., commonly known as grape is a major fruit crop in the world. Grapes seem to confer health benefits due to their chemical components, biological and antioxidant activities. The present study is conducted to evaluate the biochemical constituents, antioxidant, and antimicrobial potential of ethanolic grape peduncles (EGP) extract. The result of phytochemical analysis revealed the presence of various phytochemicals such as flavonoid, tannin, carbohydrates, alkaloids, cardiac glycoside, phenol, steroid, terpenoids, quinones and anthraquinones. Furthermore, total phenolic content (TPC) and total flavonoid contents (TFC) were 7.35 ± 0.25 mg GAE/g (Gallic Acid Equivalent per gram) and 29.67 ± 0.13 mg QE/g (Quercetin Equivalent per gram) respectively. DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging assay revealed IC₅₀ = 159.3 μg/mL. The antibacterial and antifungal study disclosed that the extract was highly potent against Salmonella typhi with maximum zone of inhibition of 27.2 ± 1.60 mm and Epidermophyton floccosum with 74 ± 1.81% inhibition. The extract was analyzed for its cytotoxicity and antileishmanial activity and showed no activity against HeLa cell line and promastigotes of Leishmania major. Elements Fe, Mn, Ni, Pb and Cd were determined by atomic absorption spectroscopy and approximately 50 compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS). Current work suggest that grape peduncles can be a promising source of bioactive medicinal component.

Comparative study of physicochemical and functional properties of soaked, germinated and pressure cooked Faba bean

Faba bean flours (germinated, soaked, cooked and raw) were evaluated for physiochemical and functional properties. The flour samples exhibited considerable amounts of carbohydrates (58.79-66.19 g/100 g) and proteins (21.9-29.1 g/100 g). Soaked faba bean (SFB) (29.1 g/100 g) and raw faba bean (RFB) (25.70 g/100 g) flour contained significantly higher amount of protein than germinated faba bean (GFB) and pressure cooked faba bean (PCFB). The physicochemical and functional composition of GFB and PCFB were improved compare to raw flour. Physical and functional properties such as water absorption index (2.97 g/g) and foaming stability (140.13 mL/100 mL) were increased by germination. The functional properties of pressure-cooked faba bean such as water solubility index (2.12 g/100 g) and water absorption capacity (2.02 g/g) were higher than other flour samples. The microstructure of legume flour samples explained that the starch granules of raw flours were smooth, oval and granular structure whereas soaked, germinated and cooked flours showed damaged starch granules. The effect of soaking, germination and pressure-cooking demonstrated significant variations in functionals characteristics of faba bean flour. Therefore, various processing conditions can be combined to obtain the desired characteristics in faba bean-based food products.

Prevalence of fungi in fresh tomatoes and their control by chitosan and sweet orange (Citrus sinensis) peel essential oil coating

BACKGROUND

Fungal contamination is a major cause of food spoilage. There is an urgent need to find and characterize natural preservatives. This study evaluates the prevalence of fungi in tomatoes and their control by using essential oil (EO) from sweet orange peel. Essential oils were extracted from dried and fresh sweet orange peels by using n-hexane and ethanol as extraction solvents. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) analyses were performed to identify the chemical composition of the EO. A combination of chitosan (CS) and EO was used to control the fungal decay of tomatoes inoculated with Aspergillus niger and Penicillium citrinum.

RESULTS

Tomatoes obtained from local markets and supermarkets showed a high prevalence of Aspergillus and Penicillium spp. Essential oils extracted by ethanol from dried peels showed complete inhibition of A. niger and P. citrinum and hyphal degradation at a minimum inhibitory concentration (MIC) of 100 μL mL^-1 . The combination of EO with chitosan (2%) as a coating, effectively controlled the fungal decay of tomatoes until the eighth day of storage at 25 °C.

CONCLUSION

Due to their edible nature, and their antifungal and preservative potential, EO- and CS-based coatings can be used to extend the shelf life of tomatoes and other agriculture commodities. Essential oil- and CS-based coating can be used as alternative to synthetic preservatives, which are associated with various health hazards. © 2021 Society of Chemical Industry.

Gastrointestinal parasitic infections of buffaloes (Bubalus bubalis) in Sarawak Borneo: Prevalence, risk factors, and farming practices

The objectives of this study were to investigate the prevalence and associated risk factors for gastrointestinal (GI) parasites in buffaloes from various areas of Sarawak, and to assess current management practices of GI parasites among farmers. Faecal samples were collected from 15 farms and 129 animals, as well as data on farm and animal-based characteristics. A total of 129 faecal samples were examined for GI parasites using a modified McMaster and sedimentation. Association between potential risk factors and the prevalence of GI parasites was investigated using Chi-square statistic. The prevalence of Paramphistomum sp., strongyles, and coccidia were 75.2% (95% CI±7.5), 52.7% (95% CI±8.6) and 48.1% (95% CI±8.6), respectively. Farms which had a grazing area less than 50 acres in size had significantly higher prevalence of strongyles (70.5%, χ² = 8.34, P = 0.004) and paramphistomes (88.6%, χ² = 6.46, P = 0.01) relative to farms with a larger grazing area (43.5% and 68.2%, respectively). Prevalence of strongyles was lower in farms that did not implement a cut- and-carry system (45.6%, χ² = 4.17, P = 0.04) in comparison to those that did (64%). The prevalence of paramphistomes was higher on farms with more than 40 animals (80.6%, χ² = 3.18, P = 0.05) relative to farms with fewer animals. The majority of farmers surveyed (67.9%) showed awareness of GI parasite infection and reported that they recognized the associated symptoms. Most farmers practised deworming, and ivermectin was the most commonly used anthelminthic (60.4%); only 1.9% of farmers used albendazole. Overall this study revealed a high prevalence of GI parasites in buffalo in Sarawak. Although farmers report they are aware of parasitic diseases, further education is still required. This could include how they can successfully implement on-farm changes to reduce the prevalence of GI parasites in their herds.

Cow- and herd-level factors associated with lameness in dairy farms in Peninsular Malaysia

Lameness is a major welfare issue in dairy cows. This study was aimed at investigating the cow- and herd -level factors associated with lameness in dairy farms from four states in Peninsular Malaysia. The study population was 1001 lactating cows from 28 dairy farms located in Selangor (n = 9), Perak (n = 8), Negeri Sembilan (n = 6) and Johor (n = 5). Lameness was assessed by locomotion scoring. Individual cow characteristics such as breeds, parity, body condition score (BCS), hock condition, leg hygiene, presence of claw lesion and claw overgrowth were recorded. Data on herd characteristics, management practices and housing design were collected by on-farm inspection and farmers' interview. Mixed-eff ;ects logistic regressions were used to model the data and to assess the factors associated with lameness. Cow-level lameness prevalence was 34.2 % (95 % CI 22.2-50.0 %), with all the farms having at least one case of lameness. Claw lesions were recorded in 470 cows (46.9 %; CI 33.3-63.3 %) of which 296 (62.9 %) of them were lame. Of these, 78.9 % of the lesions were present on the rear feet and 25.5% of the cows had more than one foot affected. The proportion of cows having non-infectious and infectious claw lesions were 81.9 % and 18.1 %, and the predominant claw lesions were sole ulcers (24.9 %), white line disease (19.6 %), sole haemorrhage (10.2%), swelling of coronet (9.6 %), toe ulcers (8.4 %), and digital dermatitis (5.6%). Cows at third or more parities had higher odds of lameness (OR = 2.2; 95 % CI 1.2-4.1) compared to primiparous cows. Low BCS (< 2.5) increased the odds of lameness (OR = 4.8; 95 % CI 2.9-7.9) relative to cows with moderate BCS, and cows with hair loss around the hock (OR = 1.4; 95 % CI 1.1-1.9) relative to those with normal hock condition. Greater odds of being lame was observed in cows having claw lesion (OR = 15.2; 95 % CI 10.4-19.2) and those with overgrown claw (OR = 3.3; 95 % CI 2.4-4.5). There was increased odds of lameness in farms with high stocking density (OR = 1.8; 95 % CI 1.1-3.1), concrete floored walkways (OR = 1.9; 95 % CI 1.0-3.6), dirty floors (OR = 2.3; 95 % CI 1.9-3.7), and practicing preventive claw trimming (OR = 2.3; 95 % CI 1.9-4.6). Based on the high lameness prevalence, these findings could assist dairy farmers to make informed decisions on areas to implement on-farm changes to reduce lameness in the studied herds.

Enhanced yield of Scenedesmus obliquus biomacromolecules through medium optimization and development of microalgae based functional chocolate

The freshwater green microalga Scenedesmus obliquus was cultivated to enhance the contents of proteins, carbohydrates and lipids by using Box-Behnken experimental design. S. obliquus was cultured under phototrophic conditions by using Bold's Basal Medium with different cultivation parameters including pH (7, 8 and 9), salinity (10, 30 and 50 mM), and nitrogen source (0.125, 0.5 and 1 g/L). The highest biomass yield (64.9 ± 0.94 mg/L/day) was obtained by using optimized medium at a salinity concentration of 30 mM (w/v), and nitrogen sources of 0.125 g/L. The maximum content of protein, lipid and carbohydrates from S. obliquus optimized medium were 342.19 ± 0.28 mg/g, 241.41 ± 4.32 mg/g and 288.05 ± 1.12 mg/g of dry wt. respectively. The amino acid and fatty acid analysis of S. obliquus biomass indicated the presence of significant amount of essential amino acids and essential fatty acids. Furthermore, chocolate crispy bar was developed by fortification with encapsulated freeze-dried S. obliquus and evaluated for its oxidative stability and sensory analysis. The chocolate fortified with microalgae can be a potential source of essential fatty acids and amino acids in addition to other bioactive compounds.

Restriction of dietary non-phytate phosphorus on growth performance and expression of intestinal phosphate cotransporter genes in broilers

Effects of dietary non-phytate phosphorus (nPP) restriction on growth and duodenal type IIb sodium-dependent phosphate cotransporter (NaPi-IIb) genes were observed. A total of 432 one-day old Cobb500 male broiler chickens in 36 cage pens were divided into 6 groups with each group containing 6 pens. Each group was treated with one of the diets containing 0.33, 0.37, 0.41, 0.45, 0.49, and 0.53% of nPP up to 14 D. During 15 to 31 D, birds were treated with one of the diets containing 0.23, 0.27, 0.31, 0.35, 0.39, and 0.43% of nPP. Level of Ca was kept the same across all treatments. Dietary nPP level influenced (P < 0.001) weight gain and feed intake in both growth phases, whereas effect on feed per gain ratio was seen only in the second phase. Toe ash, tibia ash, and tibia breaking strength responded to treatments (P < 0.01) at 14 D. Only tibia ash content was significantly improved (P < 0.001) at 31 D. Growth and bone parameters linearly improved with an increase in dietary nPP content (P < 0.05). Above dietary nPP 0.41% and 0.31% for first phase and second phase, respectively, no significant improvement was seen. Duodenal NaPi-IIb mRNA overexpressed with a decrease in dietary nPP in both phases (P < 0.05). Relative expression of NaPi-IIb in lowest nPP group were 2.2 folds higher in the first phase and 3.6 folds higher in the second phase compared to respective highest nPP groups of each phase. No significant change in NaPi-IIb expression was seen above 0.37% of dietary nPP for 14 D and 0.31% of dietary nPP for 31 D. Dietary requirements of nPP 0.41% for 0 to 14 D and 0.31% for 15 to 31 D were adequate for optimal growth and bone parameters. This study fills the gap in understanding of intestinal NaPi-IIb expression in response to dietary nPP restriction in broilers older than 21 D of age.

Ochratoxin A detection in coffee by competitive inhibition assay using chitosan-based surface plasmon resonance compact system

This study demonstrates the evaluation of ochratoxin A (OTA) in coffee on compact surface plasmon resonance (SPR) biosensors based on crosslinked chitosan and carboxymethyl chitosan nanomatrix substrates. Ochratoxin A is a toxic secondary metabolite widely produced by Aspergillus and Penicillium fungi and requires regular quantification and detection in food samples. The gold coated SPR chips were synthesized with chitosan and carboxymethyl chitosan through spin coating technique. The SPR nanomatrix chips were used for the immobilization of ochratoxin A-bovine serum albumin (OTA-BSA) conjugate to develop a competitive inhibition immunoassay. The monoclonal ochratoxin A antibodies (mAb-OTA) were used as biological receptors for the detection of OTA in buffer and coffee samples. The limit of detection (LOD) in coffee for chitosan (CS) and carboxymethyl chitosan (CMC) substrates was 5.7 ng/mL and 3.8 ng/mL, respectively. Compact surface plasmon resonance (SPR) system based on chitosan-based (CS-AU) nanomatrix substrates provides a platform for the detection of ochratoxin A with high sensitivity, accuracy, ease-of-use and cost-effectiveness. This compact SPR system can be used at farm and industrial levels for the detection of OTA in food matrices.

Culled banana resistant starch-soy protein isolate conjugate based emulsion enriched with astaxanthin to enhance its stability

The conjugates of biomacromolecules such as proteins and polysaccharides have potential to stabilize the emulsion system and encapsulate valuable bioactive compounds for biofortification in food systems. In this study, native banana starch (NBS) was isolated from green culled banana and modified into resistant starch (type III) by lintnerization followed by autoclaving-cooling process, resulting in lintnerized-autoclaved banana starch (LABS). Soy protein isolate (SPI) was used for developing the polysaccharide-protein conjugates i.e. LABS-SPI conjugate and used as wall material to stabilize the oil-in-water emulsion system. LABS-SPI conjugate emulsions were subjected to in vitro digestion model and oxidative stability evaluation. Furthermore, the emulsion system was enriched with astaxanthin and evaluated for its stability. The chemical finger printing of LABS-SPI conjugates showed stretching in immine and enaminol group of Schiff's bases, the CN stretching of Amadori product. During in vitro digestion LABS-SPI conjugate emulsion showed that the presence of resistant starch had an influence on the droplet digestion process and significantly (p < 0.05) lower free fatty acid release compared to emulsions stabilized by SPI alone. LABS-SPI conjugate emulsion system demonstrated higher stability of astaxanthin at storage temperatures (6, 20 and 37 °C), and can be used for biofortification of food and pharmaceutical formulations.

Knowledge, attitude and perception regarding antimicrobial resistance and usage among ruminant farmers in Selangor, Malaysia

The increasing public health problem of antimicrobial resistance (AMR) has been linked to the extensive antimicrobial use (AMU) in food animals. We conducted a survey among ruminant farmers in Selangor, Malaysia to assess their level of awareness on AMR, attitudes towards AMU, and determinants that influence their practices. The survey was developed in English and Malay, validated, and administered to ruminant farmers in Selangor. A total of 84 farmers (response rate of 55%) completed the structured questionnaire. They appeared to be little aware of AMR and the impact on animals and public health. Indications of inappropriate AMU include their misconception on conditions requiring antibiotic therapy and easy accessibility to antibiotics. More than 70% (60/84) of the respondents believed that all sick animals need to be given antimicrobials. Half of the farmers especially those involved in the production of small and large ruminants; namely mixed ruminant farmers (MRF) (63%, 31/49) indicated that antimicrobials do not have any side effects in animals. Sixty-four percent (54/84) of the farmers have stored antimicrobials in their farms of which the practice was more common (P = 0.02) among the MRF compared to the single ruminant farmers (SRF). Although most of the farmers felt good farm biosecurity will help reduce AMU, they were indifferent regarding using antimicrobials only when prescribed by a veterinarian and non-storage of antimicrobials for later uses. Farmers with larger herd size (>100 animals/herd) and few years of farming experience agreed more to the suggestions about their role and that of veterinarians respectively in reducing the drivers of AMR. These areas might need to be considered by advisors to inform ruminant farmers on AMR and to encourage them for prudent AMU in food-producing animals.

Reinforced cassava starch based edible film incorporated with essential oil and sodium bentonite nanoclay as food packaging material

Biodegradable packaging in food materials is a green technology based novel approach to replace the synthetic and conventional packaging systems. This study is aimed to formulate the biodegradable cassava starch based films incorporated with cinnamon essential oil and sodium bentonite clay nanoparticles. The films were characterized for their application as a packaging material for meatballs. The cassava starch films incorporated with sodium bentonite and cinnamon oil showed significant antibacterial potential against all test bacteria; Escherichia coli, Salmonella typhimurium and Staphylococcus aureus. Antibacterial effect of films increased significantly when the concentration of cinnamon oil was increased. The cassava starch film incorporated with 0.75% (w/w) sodium bentonite, 2% (w/w) glycerol and 2.5% (w/w) cinnamon oil was selected based on physical, mechanical and antibacterial potential to evaluate shelf life of meatballs. The meatballs stored at ambient temperature in cassava starch film incorporated with cinnamon oil and nanoclay, significantly inhibited the microbial growth till 96 h below the FDA limits (10⁶ CFU/g) in foods compared to control films that exceeded above the limit within 48 h. Hence cassava starch based film incorporated with essential oils and clay nanoparticles can be an alternate approach as a packaging material for food industries to prolong the shelf life of products.

Extraction and characterization of proteins from banana (Musa Sapientum L) flower and evaluation of antimicrobial activities

Ultrasonic assisted alkaline extraction of protein from banana flower was optimized using response surface methodology. The extracted proteins were characterized by Fourier transform infrared spectroscopy and molecular weight distribution was determined by gel electrophoresis. The maximum protein yield of 252.25 mg/g was obtained under optimized extraction conditions: temperature 50 °C, 30 min extraction time and 1 M NaOH concentration. The alkaline extraction produced a significantly high protein yield compared to enzymatic extraction of banana flower. Chemical finger printing of proteins showed the presence of tyrosine, tryptophan and amide bonds in extracted protein. Alkaline and pepsin assisted extracted banana flower proteins showed characteristic bands at 40 and 10 kDA, respectively. The extracted proteins showed antibacterial effects against both gram positive and gram negative bacteria. The high protein content and antimicrobial activity indicate the potential applications of banana flower in the food and feed industry.

Screening of antibiotic residues in fresh milk of Kathmandu Valley, Nepal

The prevalence of two groups of antibiotics; namely penicillin and sulfonamides was studied in fresh milk available in Kathmandu Valley of Nepal. The milk samples (n = 140) were collected from three different sources; individual farmers, cottage dairies and organized dairies of Kathmandu valley. Qualitative and semi-quantitative analysis with rapid screening kits revealed that 23% samples were positive for antibiotic residues in the fresh milk for penicillin and sulfonamide groups (1-256 µg/kg). High performance liquid chromatography (HPLC) analyses detected 81% samples positive for amoxicillin (68-802 µg/kg), 41% for sulfadimethoxine (31-69 µg/kg), 27% for penicillin G (13-353 µg/kg), and 12% for ampicillin (0.5-92 µg/kg). Due to the precision and accuracy of liquid chromatography method, it detected more positive samples and consequently presented higher prevalence than the rapid screening kits. The antibiotic residues were found above the maximum residue limits that presented serious threat to consumer health and raised a serious concern regarding the implementation and monitoring of international regulations in developing countries.

Extraction of anthocyanins from pericarp and lipids from seeds of mangosteen (Garcinia mangostana L.) by Ultrasound-assisted extraction (UAE) and evaluation of pericarp extract enriched functional ice-cream

Ultrasound-assisted extraction (UAE) was used to extract the anthocyanins from pericarp and lipids from the seeds of mangosteen. The optimum time for extraction of anthocyanin by maceration method and shaking water bath was 6 and 4 h, respectively, whereas, it was 5 min only for ultrasonic assisted extraction method. The anthocyanin content, extracted by UAE, was 23.54 mg Cyn-3-Glu/100 g. The regression equation derived by response surface methodology (RSM), was used to predict the anthocyanin content extracted by using UAE. The gas chromatography-flame ionized detector analysis showed that mangosteen seed contained both saturated (palmitic acid, 4.66 g/100 g; stearic acid, 47.64 g/100 g) and unsaturated fatty acids (oleic acid, 28.62 g/100 g; linoleic acid, 14.68 g/100 g). The mangosteen ice-cream exhibited up to 83.6 and 75.1 % DPPH inhibition, on addition of 2 and 1 % mangosteen pericarp extract respectively, where as control only 52.6 %.