Multi-isotope evidence of population aggregation in the Natufian and scant migration during the early Neolithic of the Southern Levant.

Human mobility and migration are thought to have played essential roles in the consolidation and expansion of sedentary villages, long-distance exchanges and transmission of ideas and practices during the Neolithic transition of the Near East. Few isotopic studies of human remains dating to this early complex transition offer direct evidence of mobility and migration. The aim of this study is to identify first-generation non-local individuals from Natufian to Pre-Pottery Neolithic C periods to explore the scope of human mobility and migration during the Neolithic transition in the Southern Levant, an area that is central to this historical process. The study adopted a multi-approach resorting to strontium (87Sr/86Sr), oxygen (δ18OVSMOW) and carbon (δ13C) isotope ratio analyses of tooth enamel of 67 human individuals from five sites in Jordan, Syria, and Israel. The isotope ratios point both to a significant level of human migration and/or mobility in the Final Natufian which is compatible with early sedentarism and seasonal mobility and with population aggregation in early sedentary hamlets. The current findings, in turn, offer evidence that most individuals dating to the Pre-Pottery Neolithic were local to their respective settlements despite certain evidence of non-locals. Interestingly, isotopic data suggest that two possible non-local individuals benefitted from particular burial practices. The results underscore a decrease in human mobility and migration as farming became increasingly dominant among the subsistence strategies throughout the Neolithic transition of the Southern Levant.

Emergence of corpse cremation during the Pre-Pottery Neolithic of the Southern Levant: A multidisciplinary study of a pyre-pit burial.

Renewed excavations at the Neolithic site of Beisamoun (Upper Jordan Valley, Israel) has resulted in the discovery of the earliest occurrence of an intentional cremation in the Near East directly dated to 7031-6700 cal BC (Pre-Pottery Neolithic C, also known as Final PPNB, which spans ca. 7100-6400 cal BC). The funerary treatment involved in situ cremation within a pyre-pit of a young adult individual who previously survived from a flint projectile injury. In this study we have used a multidisciplinary approach that integrates archaeothanatology, spatial analysis, bioanthropology, zooarchaeology, soil micromorphological analysis, and phytolith identification in order to reconstruct the different stages and techniques involved in this ritual: cremation pit construction, selection of fuel, possible initial position of the corpse, potential associated items and funerary containers, fire management, post-cremation gesture and structure abandonment. The origins and development of cremation practices in the region are explored as well as their significance in terms of Northern-Southern Levantine connections during the transition between the 8th and 7th millennia BC.

High-pressure effects on the proteolytic enzymes of sea bass (Dicentrarchus labrax L.) fillets.

High-pressure processing is a nonthermal technique ensuring food product safety and enabling a longer shelf life. The purpose of this experiment was to evaluate the effect of high pressure on the main proteolytic enzymes involved in fish muscle degradation during storage. Enzymes were extracted with sarcoplasmic proteins from Dicentrarchus labrax sea bass white muscle. Activity of cathepsins B, D, H, and L was quantified in protein extract, whereas calpain activity was evaluated after isolation from its endogenous inhibitor. High-pressure processing up to 500 MPa enhanced the activity of cathepsin B, H, and L, whereas the activity of cathepsin D increased up to 300 MPa and decreased above 300 MPa. With regard to calpain activity, high-pressure processing led to a decrease of activity, which was zero above 400 MPa. We suggest a leading explanation based on simultaneous deactivation of enzymes and an increase of liberation from lysosomes for cathepsins and on dissociation of subunits for calpains.

Pressure shift freezing of pork muscle: effect on color, drip loss, texture, and protein stability.

Cylindrical specimens (50 mm diameter and 160 mm length) of fresh pork muscle (boneless rib portions) packed in plastic bags were frozen by pressure shift freezing (PSF) at 100, 150, and 200 MPa, air blast freezing (ABF), and liquid immersion freezing (LIF). Temperature and phase transformations of the muscle tissue were monitored during the freezing process at three locations: center, midway between the center and the surface, and near the surface. Pork muscle quality changes [color, drip loss (both thawing and cooking), texture (shear force), and protein stability (DSC thermal profiles)] were evaluated after thawing the frozen samples at room temperature (20 degrees C). Employing pressures above 150 MPa caused very significant (P < 0.01) color changes in pork muscle during the PSF process. The PSF process reduced thawing drip loss of pork muscle but did not cause obvious changes in total drip loss following thawing and subsequent cooking. PSF at 150 and 200 MPa resulted in considerable denaturation of myofibrillar proteins of pork muscle. The PSF process also caused an increase in the pork muscle toughness as compared with that of unfrozen, ABF, and LIF samples.

Physicochemical modifications of high-pressure-treated soybean protein isolates.

Changes induced by high pressure (HP) treatment (200-600 MPa) on soybean protein isolates (SPI) at pH 3 (SPI3) and pH 8 (SPI8) were analyzed. Changes in protein solubility, surface hydrophobicity (Ho), and free sulfhydryl content (SH(F)) were determined. Protein aggregation and denaturation and changes in secondary structure were also studied. An increase in protein Ho and aggregation, a reduction of free SH, and a partial unfolding of 7S and 11S fractions were observed in HP-treated SPI8. Changes in secondary structure were also detected, which led to a more disordered structure. HP-treated SPI3 was partially denatured and presented insoluble aggregates. A major molecular unfolding, a decrease of thermal stability, and an increase of protein solubility and Ho were also detected. At 400 and 600 MPa, a decrease of the SH(F) and a total denaturation were observed.