Sporulation and Biofilms as Survival Mechanisms of Bacillus Species in Low-Moisture Food Production Environments.

Low-moisture foods (LMF) have clear advantages with respect to limiting the growth of foodborne pathogens. However, the incidences of Bacillus species in LMF reported in recent years raise concerns about food quality and safety, particularly when these foods are used as ingredients in more complex higher moisture products. This literature review describes the interlinked pathways of sporulation and biofilm formation by Bacillus species and their underlying molecular mechanisms that contribute to the bacteriums' persistence in LMF production environments. The long-standing challenges of food safety and quality in the LMF industry are also discussed with a focus on the bakery industry.

Alkyl chain length modulates antioxidant activity of gallic acid esters in spray-dried emulsions.

Lipid oxidation is a well-recognized issue in dried food emulsions, such as infant milk formula. Antioxidants can be used to mitigate this issue; however, their efficiency in such complex systems is far from understood. In this study, antioxidant polarity is varied through the alkyl chain length of gallic acid esters (0-16 carbon atoms) incorporated to O/W emulsions that are subsequently spray-dried. During processing and subsequent storage of the samples, antioxidants with more than eight carbon atoms are effective. Both for encapsulated fat and surface free fat, we observe a slight cut-off effect, meaning that beyond eight alkyl groups, a more nonpolar antioxidant is slightly less effective. Depending on the antioxidant polarity, lipid oxidation is faster either in the encapsulated or in the surface free fat. The insights obtained contribute to understanding lipid oxidation in low moisture food emulsions, and thus lead to effective antioxidant strategies.

Applications of nonthermal plasma technology on safety and quality of dried food ingredients.

Cold plasma technology is an efficient, environmental-friendly, economic and noninvasive technology; and in recent years these advantages placed this novel technology at the centre of diverse studies for food industry applications. Dried food ingredients including spices, herbs, powders and seeds are an important part of the human diet; and the growing demands of consumers for higher quality and safe food products have led to increased research into alternative decontamination methods. Numerous studies have investigated the effect of nonthermal plasma on dried food ingredients for food safety and quality purposes. This review provides critical review on potential of cold plasma for disinfection of dried food surfaces (spices, herbs and seeds), improvement of functional and rheological properties of dried ingredients (powders, proteins and starches). The review further highlights the benefits of plasma treatment for enhancement of seeds performance and germination yield which could be applied in agricultural sector in near future. Different studies applying plasma technology for control of pathogens and spoilage micro-organisms and modification of food quality and germination of dried food products followed by benefits and current challenges are presented. However, more systemic research needs to be addressed for successful adoption of this technology in food industry.

Relationship among pH, generation of free amino acids, and Maillard browning of dried Japanese common squid Todarodes pacificus meat.

Relationship among pH, generation of free amino acids (FAAs), and Maillard browning was investigated in Japanese common squid during air drying at 40 °C to prevent its discoloration. In the surface color measurement, increase in the b* value which is an indicator for Maillard browning of the dried squid was mitigated at pH 4.0-6.0 and accelerated at pH 7.5-9.0. Adjusting the pH to 5.5 effectively suppressed increasing of the b* value (p < 0.05). Arginine (Arg) generation involved in the Maillard reaction, was inhibited in the dried squid at pH 5.5 (p < 0.05). Maillard reactivities between ribose and amino acids were lower at pH 4.0 than at pH 5.5 (p < 0.05). These results indicate that browning of the dried squid is significantly suppressed at pH 5.5. Moreover, suppression of Arg generation is more effective than weakening of Maillard reactivity between ribose and Arg, in mitigating Maillard browning of the dried squid at an acidic pH.

Guacamole powder: standardization of the spray drying process / Guacamole en polvo: estandarización del proceso de secado por aspersión

Background: Guacamole is a sauce or dressing composed of avocado pulp and other ingredients. Guacamole powder is an important advance in the generation of value added for the avocado chain, as it is an alternative product with the potential to be used by the final consumer. Objectives: The aim of this study was to standardize the spray drying process for guacamole powder using the response surface methodology. Methods: Four independent variables were taken into account for the experiment design: atomizing disk speed (ADS), air inlet temperature (AIT), air outlet temperature (AOT) and vacuum pressure (VP). In addition, the following dependent variables were considered: water activity (aw), moisture (Xw), solubility (S), hygroscopicity (H), color (L*, a* and b*), extractable oil content (EO), peroxide index (PI) and particle size (D10, D50 and D90). Likewise, the following two dependent variables associated with the process were identified: yield (Y) and deposit formation (DF). Results: The best conditions for the process were obtained with ADS = 27451 rpm, AIT = 168ºC, AOT = 90ºC and VP = 1.77 ″H2O. These conditions yielded guacamole powder with the desired properties, namely: maximum Y, S, L*, b*, EO and minimal DF, aw, Xw, H, a*, PI, D10, D50, D90. Conclusions: The spray drying process is an effective technology that provides added value to avocado, the ADS being the independent variable that has the greatest impact on the quality of powdered guacamole.

Antecedentes: El guacamole es una salsa o aderezo compuesto por pulpa de aguacate y otros ingredientes. El guacamole en polvo representa un avance importante en la generación de valor agregado de la cadena del aguacate, al identificarse como un producto alternativo con potencial uso por el consumidor final. Objetivos: El objetivo del presente estudio fue estandarizar el proceso de secado por aspersión para la obtención de guacamole en polvo, utilizando la metodología de superficie de respuesta. Métodos: Para el diseño experimental se consideró cuatro variables independientes: velocidad del disco atomizador (VDA), temperatura de entrada de aire (TEA), temperatura de salida de aire (TSA) y presión de vacío (PV). Además, se consideraron las siguientes variables dependientes: actividad de agua (aw), humedad (Xw), solubilidad (S), higroscopicidad (H), color (L* , a* y b* ), contenido de aceite extraíble (AE), índice de peróxido (IP) y tamaño de partícula (D10, D50 y D90). Además, se determinaron dos variables dependientes asociadas al proceso, rendimiento (Y), y la formación de depósito (FD). Resultados: La mejor condición de proceso se alcanzó con VDA = 27451 rpm, TEA = 168ºC, TSA = 90ºC y PV = 1,77 ″H2O. En esta condición se obtuvo guacamole en polvo con propiedades deseadas máximo R, S, L*, b*, AE y mínima FD, aw, Xw, H, a* , IP, D10, D50, D90. Conclusiones: El proceso de secado por aspersión es una tecnología efectiva que proporciona valor agregado al aguacate, siendo la VDA la variable independiente que mayor afectación tiene sobre la calidad del guacamole en polvo.

Chemical composition, antioxidant capacity, and sensory quality of dried jujube fruits as affected by cultivar and drying method.

The aim of this study was to determine the effect of different dying methods, such as convective drying (CD: 50, 60, 70 °C), vacuum-microwave drying (VMD: 120, 480, 480-120 W), a combination of convective pre-drying and vacuum-microwave finish drying [(CPD (60 °C)-VMFD (480-120 W)], and freeze-drying (FD) on key quality parameters of dried jujube fruits (cv. "GAL", "MSI", and "PSI"). The parameters studied included bioactive compounds (flavan-3-ols and flavonols, identified by LC-PDA-MS, and vitamin C), antioxidant capacity (ABTS and FRAP), and sensory attributes (e.g. hardness, jujube-ID, and sweetness). The best quality of the dried product (high contents of bioactive compounds and high intensity of key sensory attributes) was found in fruits treated by FD and VMD 480-120 W. The best cultivars were "PSI" and "GAL" from the point of view of bioactive content and sensory quality, respectively.