Valeria Iaconisi

Use of Tenebrio molitor larvae meal as protein source in broiler diet: Effect on growth performance, nutrient digestibility, and carcass and meat traits

The aim of this research was to study the effect of insect meal from larvae ( larvae meal [TML]) as complete replacement of soybean meal (SBM) on growth performance, nutrient digestibility, and carcass and meat traits of broilers. A total of eighty 30-d-old male Shaver brown broilers were homogenously divided into 2 groups (each consisting of 8 replicates of 5 birds). Up to 62 d of age, the groups were fed 2 isoproteic and isoenergetic diets differing for the ingredient used as the main protein source: the control group was fed a corn-SBM-based diet, whereas in the TML group, the SBM was completely replaced by TML. Broiler growth performance was measured during the trial. At 62 d of age, 2 broilers per replicate (16 per group) were slaughtered and apparent ileal digestibility coefficients and carcass and meat traits were determined. The use of TML as the main protein source in the broiler diet had no significant effect on most growth performance and carcass traits and chemical and physical properties of meat, the latter being important for marketing purposes. The feed conversion ratio in the entire experimental period (from 30 to 62 d) was improved in the TML group compared with the SBM group ( < 0.05). The apparent ileal digestibility coefficients of DM, OM, and CP in broilers fed the SBM diet were greater ( < 0.01) than the other group. The full digestive system in broilers fed SBM had a lower ( < 0.05) absolute and relative weight than that of broilers fed TML. Also, the weight and the percentage of the spleen in the SBM group were lower ( < 0.05) than those in the TML group. The length of the entire intestine in the group fed TML was greater ( < 0.05) than the other group and the same happened when intestinal length was expressed as percentage of broiler BW ( < 0.05). Among the different intestinal tracts, the ileum and ceca of broilers fed TML had a greater ( < 0.05) length than that of broilers fed SBM. Also, ceca weight (as an absolute value or percentage on live weight) in broilers fed TML was greater ( < 0.05) than that of broilers fed SBM. Breast pH and cooking losses in broilers fed TML were greater ( < 0.05) than those of broilers fed SBM. Chemical characteristic of meat obtained from right breast of slaughtered broilers were unaffected by dietary treatments. larvae meal can be a suitable alternative protein source for growing broilers and also when used as principal protein contributor to the diet.

Inclusion of Hermetia illucens larvae meal on rainbow trout (Oncorhynchus mykiss) feed: effect on sensory profile according to static and dynamic evaluations

BACKGROUND Diet implementation with insect meal has aroused increased attention in aquaculture considering the advantages of this new protein source. The effect of Hermetia illucens meal (HI) inclusion in diets on rainbow trout physical-chemical and sensory properties was evaluated. Three diets were prepared: HI0, HI25, HI50, with 0, 25 and 50% of HI replacing fish meal, respectively. Fillet sensory profiles were described by descriptive analysis and temporal dominance of sensation methods. Cooking loss, Warner-Bratzler shear force, proximate analysis, and fatty acid composition were also determined. RESULTS Diets significantly affected fillets sensory profile. Descriptive analysis indicated significant changes in perceived intensity of aroma, flavour and texture descriptors as a function of diet composition. Temporal dominance of sensation evaluations provided information on dominance and evolution of sensations perceived in fillets from different diets. The first sensations perceived as dominant were related to texture attributes, followed by flavours. Dominance of fibrousnesses decreased with the increase of HI in the diet. Boiled fish, algae flavours and umami taste clearly dominated the HI0 dynamic profile. The onset of metallic flavour dominance characterised HI25 and HI50. No differences in physical parameters were detected. Principal component analysis highlighted the relationship between sensory attributes and physico-chemical parameters. CONCLUSION The sensory description of fillets indicated that HI inclusion induces significant differences in the perceived profile.

Can the inclusion of black soldier fly (Hermetia illucens) in diet affect the flesh quality/nutritional traits of rainbow trout (Oncorhynchus mykiss) after freezing and cooking?

Abstract Physical and chemical parameters of rainbow trout fillets were tested during 120 days of frozen storage and following cooking. The fillets were obtained from rainbow trout-fed diets where dietary fishmeal was substituted with Hermetia illucens meal at 0, 25 and 50% inclusion levels, corresponding to control (C), Hi25, and Hi50 diets. Variations in quality traits of fillets emerged after 30 days of frozen storage, however they remained almost unchanged for the other 90 days. Increasing levels of H. illucens did not affect pH, shear stress, colour and water holding capacity of fillets. Saturated fatty acids were highly present in Hi50 samples, the polyunsaturated and some monounsaturated ones were higher in C than Hi50, whereas Hi25 always assumed intermediate contents in raw and cooked samples. A medium substitution at the 25% seemed to be the most practical application of insect meal in order to not modify too much the fillets characteristics. Graphical Abstract

Quality characteristics of the Musculus longissimus dorsi from Pecora dell’Amiata reared in Tuscany

Pecora dell’Amiata sheep is registered in the Regional population register of the autochthonous endangered sheep and goat breeds, and it is a double purpose breed (meat and milk). It derives from the mount Amiata area in Tuscany. In Tuscany the sheep meat consumption occurs in particular in Easter and in Christmas time. Because of the new markets, ewe meat has shown in the last years a consumption increase. In Italy, the more consumed ovine meat is the suckling lamb meat. In the last years, this kind of meat production and consumption decreased in Italy, but the ewe meat consumption has been slowly increased, because of the spread of typical regional food, and the new market needs. The trial was performed with ewes and lambs deriving from the local breed Pecora dell’Amiata. In this work, the Musculus longissimus dorsi ( M. longissimus thoracis + lomborum ) physical-chemical and nutritional characteristics of 23 ewes and 20 lambs were compared. The ewes of the trial were over 7 years old while the lambs were on average 80 days old. Ewe meat has shown lower drip loss (4.14 vs 2.71%) and lightness (L* 38.6 vs 45.3) values, and higher PH (6.15±0.07), shear force (8.4 vs 2.31 kg), fat content (5.9 vs 2.0%). The lamb meat lipids had higher polyunsaturated fatty acid content (PUFA: 14.58 vs 9.25%) and higher PUFA/Saturated Fatty Acids (SFA) ratio (0.31 vs 0.20). The PCA analysis identified two distinct groups regarding ewe and lamb meat respectively for the fatty acids composition and the health indices. Ewe meat showed dietetic and nutritional characteristics similar to that of lamb meat. These characteristics may allow in the future, to the ewe meat valorisation, now not appreciated by Tuscan and Italian market.

Impact of black soldier fly larvae meal on the chemical and nutritional characteristics of rainbow trout fillets

The present research studied the effect of a dietary inclusion with Hermetia illucens larvae meal (Hi) on rainbow trouts fillets chemical composition. The effect of Hi inclusion in diets on rainbow trout chemical characteristics was evaluated. Trout were fed three different diets: control (C, no Hi inclusion), 25% and 50% of substitution of fish meal with Hi (Hi25 and Hi50, respectively). Fillets were analysed to quantify proximate composition, carbohydrates percentage, colour parameters, nucleotides concentration, fatty acids profile, volatile organic compounds (VOCs) and myofibrillar and sarcoplasmic concentrations. Diets did not affect proximate composition. Contrariwise, Hi50 diet decreased fillet yellowness and both substitution percentages affected negatively adenosine monophosphate concentration. Saturated fatty acids, mostly C12 : 0, increased their contents in relation with Hi inclusion at the expense of monounsaturated and polyunsaturated (both n-3 and n-6) fatty acids. Less modifications were reported in VOCs as only heptanal and octanal concentrations were affected, no new compounds appeared in relation with Hi inclusion. No modifications in proteins patterns were shown even if myofibrillar content decreased in trout fed Hi50. The results highlighted that chemical modifications occurred in fillets were related to the chemical composition of the H. illucens meal and to the percentage of inclusion in the diet. Substitution of fish meal with a precisely percentage of H. illucens meal could be a potential future solution in order to decrease the quantity of fish meal used in aquafeeds.