Does drying preserve the nutritional quality of small freshwater fish without excessive concentrations of heavy metals?

The potential of drying to preserve the nutritional quality of a small freshwater fish Henicorhynchus siamensis was assessed. Drying time to reach moisture content and water activity of 10 g/100g and 0.65 ranged from 55 h at 50 °C to 20 h at 80 °C, respectively. Dried fish powder is rich in macronutrients (protein, lipid and ash) and essential minerals (calcium, phosphorus, iron and zinc) due to water removal and despite lipid loss. It is still rich in polyunsaturated fatty acids although docosahexaenoic acid was reduced except at 60°C. Vitamin A was rapidly degraded and manganese was concentrated at high level. However, mean score for the nutritional adequacy of the 15 nutrients (SAIN) and score of nutrients to limit (LIM) show that the fish powder can be used as a food ingredient for example in the formulation of fish snack or instant soup. With the abundance of Henicorhynchus siamensis, dried fish powder from this species could contribute to food security in Cambodia, especially vulnerable people in rural areas.

Physico-Chemical Characteristics and Lipid Oxidative Stability of Zebra (Equus Burchelli) Droëwors Made Using Different Levels of Sheep Fat.

The physico-chemical properties (proximate, salt content, water activity (aw), pH) and lipid oxidation of droëwors (dried salted/spiced meat sausages) produced with zebra meat and different sheep fat levels (10, 15, and 20% by weight) measured at day 0 (before drying), day 2 (after drying at 30 °C and 40% relative humidity), and over a 90 day storage (day 17, 32, 47, 62, 77, and 92) under vacuum at 25 °C were investigated. The use of lower fat levels (10 and 15%) in the formulation resulted in higher weight loss during drying and droëwors with higher protein, ash, and salt content and lower aw and pH compared to the droëwors made with 20% fat. The pH increased (p < 0.001) during storage for all the fat levels, while the moisture content and the aw were stable as expected. TBARS values were the highest in droëwors made with 20% of fat after drying (day 2), but droëwors made with 10% of fat reached similar maximal values on day 17. Formulations containing 15% sheep fat displayed the lowest TBARS values after drying and along storage, and thus had the best characteristics in relation to oxidative stability.

Application of Fat-Tailed Sheep Tail and Backfat to Develop Novel Warthog Cabanossi with Distinct Sensory Attributes.

This study compared the use of pork backfat (PF) and fat-tailed sheep tail and backfat (SF) on the physicochemical, fatty acids and sensory attributes of warthog cabanossi. There were no differences between weight loss during drying, moisture content, pH, water activity, salt content and lipid oxidation between the cabanossi types. However, protein and ash contents were higher in PF cabanossi whilst fat content was higher in SF cabanossi. The PF cabanossi had higher polyunsaturated fatty acids (especially n-6), lower monounsaturated fatty acids whilst the saturated fatty acid content was similar between the two cabanossi products. The n-3:n-6 ratio was more beneficial in the SF cabanossi. The descriptive sensory analysis showed two distinct products where PF cabanossi scored higher for most attributes. Although SF cabanossi scored less for these attributes, this cabanossi had unique and acceptable sensory attributes. This study concluded that fat-tailed sheep tail and backfat could be used to produce a unique cabanossi product of acceptable quality.

Fermented meat sausages from game and venison: what are the opportunities and limitations?

An increase in the acceptance, demand and production of game meat and venison has been experienced globally. Game meat and venison fit into consumers' ideology of healthy and environmentally friendly meat when compared to domesticated animals. Opportunities exist to explore the use of these meat sources in developing new products, particularly as game meat and venison in their fresh state are sometimes perceived as being tough. Consumers have shown a trend for trying exciting new products with different organoleptic qualities, and fermented sausages occupy a special niche in the gastro-economic trade. In this review, the production potential of game meat and venison and its prospective use in the development of fermented sausages are discussed. Emphasis is placed on the importance of meat characteristics in textural and sensorial development as well as the safety of fermented sausages. Additionally, consumers' perception of venison and game meat is discussed. Possible areas of research and knowledge gaps are highlighted, particularly the potential use of meat with high pH and microbial load. © 2018 Society of Chemical Industry.

Physicochemical and microbiological characteristics of kitoza, a traditional salted/dried/smoked meat product of Madagascar.

Kitoza samples collected from producers in Madagascar were analyzed for their physicochemical and microbial properties. Lactic acid bacteria and coagulase-negative staphylococci were the two codominant populations with average counts of 6-7 log cfu/g. Good hygienic practices were sometimes lacking but samples were not contaminated with Salmonella, Clostridium perfringens, and Bacillus cereus and only once with Listeria monocytogenes. Staphylococcus aureus was found occasionally with higher counts in salted/dried products than in salted/smoked products. Moisture, protein, fat, and salt contents varied considerably and were on average 41.5, 43.5, 14.3, and 3.3 g/100 g, respectively, and water activity was 0.893 on average. Smoked kitoza showed higher moisture content compared to dried kitoza. Most of the smoked kitoza had a water activity higher than 0.9 which is not in accordance with their storage at ambient temperatures. Benzo(a)pyrene content was above 2 µg/kg in 11 out of 30 smoked samples (17 ± 16.5 µg/kg on average).

Effects of the addition of vinegar, weight loss and packaging method on the physicochemical properties and microbiological profile of biltong.

Biltong is an Ready to Eat (RTE) shelf stable salted/dried meat product stored under ambient conditions. The effect of vinegar addition during salting, weight loss during drying and packaging (modified atmosphere and vacuum) on the physicochemical and microbiological properties of beef biltong over a 3 months storage at 25 °C was investigated. Biltong dried to ~50% weight loss had a moisture content of ~50 g/100 g, salt content of 7.49 g/100 g and water activity >0.81 whilst biltong dried to 65% weight loss had a moisture content of 30 g/100 g, salt content of 7.14 g/100 g and water activity <0.78. Packaging method had no effect. Vinegar decreased the pH of biltong to 4.91, delayed the growth of total viable counts and reduced the coliforms count but not the yeasts and moulds. Escherichia coli was below the detection limit of 1 log cfu/g, Salmonella spp. and Listeria monocytogenes were absent and Staphylococcus aureus counts were <1.3 log cfu/g.

Physico-chemical composition and oxidative stability of South African beef, game, ostrich and pork droëwors.

Droëwors are traditional South African salted and dried sausages, made without nitrites/nitrates and non- fermented. Different meat sources (beef, game and ostrich) are traditionally used in droëwors processing, while the use of pork is uncommon, as it is said to lead to rancidity. The first part of the study analysed the physico-chemical composition of commercially available beef, game and ostrich meat droëwors (n = 20). On average, they were composed of 26.3-29.2 g/100 g moisture, 41.3-44.0 g/100 g protein, 26.2-33.1 g/100 g fat and 5.9-6.5 g/100 g ash and 5.0-5.4 pH. Water activity (0.76-0.82) was sufficiently low to ensure shelf stability at ambient temperatures. In the second part beef and pork droëwors were formulated in accordance with these results and with similar fat content, dried for 2 days (30 °C, 40% relative humidity) and stored for 26 days (25 °C, 50% relative humidity); measuring moisture, water activity, pH and lipid oxidative stability (thiobarbituric acid reactive substances (TBARS)) weekly. At day 5, moisture and thus water activity of pork droëwors was slightly higher compared to beef ones and fat and ash content slightly lower (P ≤ 0.05) despite similar weight loss. Even with slightly less fat, TBARS in pork droëwors were significantly higher after drying and throughout storage (3.83 vs 0.99 mg MDA equivalents/kg dry matter at a maximum).

Changes in the physico-chemical attributes through processing of salami made from blesbok (Damaliscus pygargus phillipsi), eland (Taurotragus oryx), fallow deer (Dama dama), springbok (Antidorcas marsupialis) and black wildebeest (Connochaetes gnou) in comparison to pork.

Drying kinetics and changes in proximate composition, pH, salt content, water activity (aw) and lipid oxidation through processing of salami made using five different game meat species were evaluated and compared to pork. Eight batches of salami from each species were made and sampled for analysis throughout processing. Processing time was a significant factor on all measured attributes whilst species affected (P ≤ .05) pH and moisture but not drying kinetics. Black wildebeest meat exhibited higher (P ≤ .05) pH than pork and other game meat (6.30 vs 5.63-5.80), which translated to higher (P ≤ .05) salami pH throughout and at the end of processing (5.77). Final pH of all other salami ranged from 5.01 to 5.28, aw ranged from 0.88 to 0.92. TBARS remained lower than 1 mg MDA equivalent/kg. The study suggests that salami from these game species, excluding black wildebeest, can be produced using the same processing parameters as conventional pork salami and obtaining similar physico-chemical attributes.

Staphylococcal ecosystem of kitoza, a traditional malagasy meat product.

Kitoza is a traditional meat product from Madagascar manufactured with strips of pork or beef. The process includes a first step of salting and mixing with spices followed by sun-drying or smoking step. As salting and drying select coagulase-negative staphylococci (CNS), our aim was to identify the CNS species in kitoza with the objective in the future of developing indigenous starters. Microbial analyses revealed that the only pathogenic bacterium enumerated was Staphylococcus aureus, which was found in 54% of the samples. The level of Enterobacteriaceae revealed a rather good hygienic quality of these products. CNS were confirmed in all the samples at high levels ranging from 5 to 7logcfu/g. Identification of CNS species in a large collection of 829 isolates revealed 9 identified species, 7 for beef and 8 for pork kitoza. There were significant difference in the distribution of CNS species according to the type of meat and the process. Staphylococcus saprophyticus was the dominant species for sun-dried or smoked beef and sun-dried pork kitoza (73-75%), while for smoked pork kitoza Staphylococcus equorum (26%), S. saprophyticus (23%), Staphylococcus succinus (23%) and Staphylococcus epidermidis (17%) co-dominated. Some CNS could be used as indigenous starters in particular to compete against S. aureus.

Colour and oxidative stability of mince produced from fresh and frozen/thawed fallow deer (Dama dama) meat.

Colour and oxidative stability of minced meat from fresh and frozen/thawed fallow deer was investigated. For the seven fallow deer harvested, half of the meat was minced fresh and half was frozen (-20°C) for 2months under vacuum prior to grinding. Surface colour attributes, myoglobin content and surface redox forms, pH and lipid oxidation of the mince were measured during eight days of display storage. Proximate composition was determined in mince on day 0, fatty acid composition on day 0 and 8. Freezing had no effect on the proximate composition or fatty acid composition of the mince. Frozen meat mince had lower (P≤0.05) total myoglobin content but higher (P≤0.05) decrease in redness (a*) during display storage, higher (P≤0.05) accumulation of metmyoglobin at the surface from day 2 and higher (P≤0.05) TBARS values. Results showed shorter colour and oxidative stability for frozen meat mince as compared to mince from fresh meat. Display storage however did not affect fatty acid composition.

Effect of steam and lactic acid treatments on the survival of Salmonella Enteritidis and Campylobacter jejuni inoculated on chicken skin.

Campylobacteriosis and salmonellosis are the most frequently reported zoonotic infectious diseases. The present work evaluated the effectiveness of steam treatment at 100 °C for 8s, a 5% lactic acid treatment for 1 min and their combination for inactivating Salmonella Enteritidis and Campylobacter jejuni inoculated on chicken skin. The impact of each treatment on the total aerobic mesophilic bacteria and the effect of rinsing after contact with lactic acid were also evaluated. Residual bacteria were counted immediately after treatment or after seven days of storage at 4 °C. Results demonstrated the immediate efficiency of the steam and the combined treatments with reductions of approximately 6 and 5 log cfu/cm2 respectively for S. Enteritidis and C. jejuni. They also showed significant reductions (equal to or >3.2 log cfu/cm2) in the total aerobic mesophilic plate count. Lactic acid had a persistent effect on pathogen growth during storage which was significantly higher when the skin was not rinsed, reaching reductions of 3.8 log cfu/cm2 for both S. Enteritidis and C. jejuni. Only the combined treatments significantly reduced the recovery of the total aerobic mesophilic bacteria during storage. The significant reductions in both pathogens and total aerobic mesophilic bacteria on treated chicken skins are possible ways to improve the safety and shelf life of the product although high levels of indigenous non-pathogenic bacteria may be beneficial due to their protective effect against potential re-contamination of chicken skin.

Feasibility of coupling dehydration-impregnation by soaking treatment of meat with fermentation by Lactobacillus sakei.

UNLABELLED: This study examined the feasibility of coupling dehydration-impregnation by soaking (DIS) with a subsequent lactic fermentation in the treatment of meat. A series of beef fillets were subjected to 3 different DIS treatments. The resulting DIS-treated fillets had 3 different characteristics in terms of water activity, salt, and fermentable sugars contents. Fillets treated with the DIS with the shortest immersion time (5 h) and the highest salt concentration in the DIS bath (100 g/L) were inoculated with Lactobacillus sakei. A control group was left without inoculation. After 24 h incubation at 25 °C, only inoculated fillets showed signs of lactic fermentation. At 24 h, these fillets had a d-lactic acid content of 68 µmol/g dry basis and a high population of L. sakei revealed by methods of plate count and quantitative PCR. DIS could therefore be compatible with a subsequent fermentation step by L. sakei. PRACTICAL APPLICATION: Traditional meat preservation processes often combine unit operations such as salting, smoking, fermentation, and drying. In tropical countries, high temperatures and high relative humidity, poor infrastructure, and improper slaughterhouse practices explain the need for more drastic processes (more salt, more water loss) for meat preservation. Dehydration-impregnation by soaking (DIS) could be used as a rapid pretreatment of meat, in order to counteract tropical conditions. This study validates a novel approach whereby DIS is coupled with lactic fermentation by surface inoculation with Lactobacillus sakei. With a final drying step this process could be used for the treatment of whole meat pieces.